Add buffer merging feature, with /buffer merge/unmerge (task #7404)

23 files changed, 1848 insertions, 997 deletions

diff --git a/src/gui/CMakeLists.txt b/src/gui/CMakeLists.txt
index f71812928..a3c7342cd 100644
--- a/src/gui/CMakeLists.txt
+++ b/src/gui/CMakeLists.txt
@@ -28,6 +28,7 @@ gui-hotlist.c gui-hotlist.h
 gui-input.c gui-input.h
 gui-keyboard.c gui-keyboard.h
 gui-layout.c gui-layout.h
+gui-line.c gui-line.h
 gui-main.h
 gui-nicklist.c gui-nicklist.h
 gui-window.c gui-window.h)
diff --git a/src/gui/Makefile.am b/src/gui/Makefile.am
index 011c543e6..92f3c4cef 100644
--- a/src/gui/Makefile.am
+++ b/src/gui/Makefile.am
@@ -44,6 +44,8 @@ lib_weechat_gui_common_a_SOURCES = gui-bar.c \
                                    gui-keyboard.h \
                                    gui-layout.c \
                                    gui-layout.h \
+                                   gui-line.c \
+                                   gui-line.h \
                                    gui-main.h \
                                    gui-nicklist.c \
                                    gui-nicklist.h \
diff --git a/src/gui/curses/gui-curses-chat.c b/src/gui/curses/gui-curses-chat.c
index d9c138cbc..4be162d9c 100644
--- a/src/gui/curses/gui-curses-chat.c
+++ b/src/gui/curses/gui-curses-chat.c
@@ -37,6 +37,7 @@
 #include "../gui-chat.h"
 #include "../gui-color.h"
 #include "../gui-hotlist.h"
+#include "../gui-line.h"
 #include "../gui-main.h"
 #include "../gui-window.h"
 #include "gui-curses.h"
@@ -67,12 +68,12 @@ gui_chat_marker_for_line (struct t_gui_buffer *buffer, struct t_gui_line *line)
     struct t_gui_line *last_read_line;
     
     /* marker is not set for buffer? */
-    if (!buffer->last_read_line)
+    if (!buffer->lines->last_read_line)
         return 0;
     
-    last_read_line = buffer->last_read_line;
-    if (!last_read_line->displayed)
-        last_read_line = gui_chat_get_prev_line_displayed (last_read_line);
+    last_read_line = buffer->lines->last_read_line;
+    if (!last_read_line->data->displayed)
+        last_read_line = gui_line_get_prev_displayed (last_read_line);
     
     if (!last_read_line)
         return 0;
@@ -87,7 +88,7 @@ gui_chat_marker_for_line (struct t_gui_buffer *buffer, struct t_gui_line *line)
         if (last_read_line == line)
             return 1;
         
-        if (line->displayed)
+        if (line->data->displayed)
             break;
         
         line = line->next_line;
@@ -440,7 +441,7 @@ gui_chat_display_word (struct t_gui_window *window,
     while (data && data[0])
     {
         /* insert spaces for align text under time/nick */
-        length_align = gui_chat_get_line_align (window->buffer, line, 0);
+        length_align = gui_line_get_align (window->buffer, line, 0);
         if ((length_align > 0) &&
             (window->win_chat_cursor_x == 0) &&
             (*lines_displayed > 0) &&
@@ -540,15 +541,17 @@ gui_chat_display_time_and_prefix (struct t_gui_window *window,
                                   int simulate)
 {
     char str_space[] = " ", str_plus[] = "+", *prefix_highlighted;
-    int i, length_allowed, num_spaces;
+    int i, length, length_allowed, num_spaces;
+    struct t_gui_lines *mixed_lines;
     
     /* display time */
-    if (window->buffer->time_for_each_line && (line->str_time && line->str_time[0]))
+    if (window->buffer->time_for_each_line
+        && (line->data->str_time && line->data->str_time[0]))
     {
         if (!simulate)
             gui_window_reset_style (GUI_WINDOW_OBJECTS(window)->win_chat, GUI_COLOR_CHAT);
         
-        gui_chat_display_word (window, line, line->str_time,
+        gui_chat_display_word (window, line, line->data->str_time,
                                NULL, 1, num_lines, count, lines_displayed,
                                simulate);
         gui_chat_display_word (window, line, str_space,
@@ -564,25 +567,73 @@ gui_chat_display_time_and_prefix (struct t_gui_window *window,
                                NULL, 1, num_lines, count, lines_displayed,
                                simulate);
     }
+
+    /* display buffer name (if many buffers are merged) */
+    mixed_lines = line->data->buffer->mixed_lines;
+    if (mixed_lines)
+    {
+        if (!simulate)
+        {
+            gui_window_set_weechat_color (GUI_WINDOW_OBJECTS(window)->win_chat,
+                                          GUI_COLOR_CHAT_PREFIX_BUFFER);
+        }
+        
+        length = gui_chat_strlen_screen (line->data->buffer->short_name);
+        num_spaces = mixed_lines->buffer_max_length - length;
+        
+        if (CONFIG_INTEGER(config_look_prefix_buffer_align) == CONFIG_LOOK_PREFIX_BUFFER_ALIGN_RIGHT)
+        {
+            for (i = 0; i < num_spaces; i++)
+            {
+                gui_chat_display_word (window, line, str_space,
+                                       NULL, 1, num_lines, count,
+                                       lines_displayed, simulate);
+            }
+        }
+        
+        gui_chat_display_word (window, line,
+                               line->data->buffer->short_name,
+                               NULL, 1, num_lines, count, lines_displayed,
+                               simulate);
+        
+        if ((CONFIG_INTEGER(config_look_prefix_buffer_align) == CONFIG_LOOK_PREFIX_BUFFER_ALIGN_LEFT)
+            || ((CONFIG_INTEGER(config_look_prefix_buffer_align) == CONFIG_LOOK_PREFIX_BUFFER_ALIGN_NONE)
+                && (CONFIG_INTEGER(config_look_prefix_align) != CONFIG_LOOK_PREFIX_ALIGN_NONE)))
+        {
+            for (i = 0; i < num_spaces; i++)
+            {
+                gui_chat_display_word (window, line, str_space,
+                                       NULL, 1, num_lines, count, lines_displayed,
+                                       simulate);
+            }
+        }
+        
+        gui_chat_display_word (window, line, str_space,
+                               NULL, 1, num_lines, count, lines_displayed,
+                               simulate);
+    }
     
     /* display prefix */
-    if (line->prefix
-        && (line->prefix[0]
+    if (line->data->prefix
+        && (line->data->prefix[0]
             || (CONFIG_INTEGER(config_look_prefix_align) != CONFIG_LOOK_PREFIX_ALIGN_NONE)))
     {
         if (!simulate)
-            gui_window_reset_style (GUI_WINDOW_OBJECTS(window)->win_chat, GUI_COLOR_CHAT);
+        {
+            gui_window_reset_style (GUI_WINDOW_OBJECTS(window)->win_chat,
+                                    GUI_COLOR_CHAT);
+        }
         
         if (CONFIG_INTEGER(config_look_prefix_align_max) > 0)
         {
             length_allowed =
-                (window->buffer->prefix_max_length <= CONFIG_INTEGER(config_look_prefix_align_max)) ?
-                window->buffer->prefix_max_length : CONFIG_INTEGER(config_look_prefix_align_max);
+                (window->buffer->lines->prefix_max_length <= CONFIG_INTEGER(config_look_prefix_align_max)) ?
+                window->buffer->lines->prefix_max_length : CONFIG_INTEGER(config_look_prefix_align_max);
         }
         else
-            length_allowed = window->buffer->prefix_max_length;
+            length_allowed = window->buffer->lines->prefix_max_length;
         
-        num_spaces = length_allowed - line->prefix_length;
+        num_spaces = length_allowed - line->data->prefix_length;
         
         if (CONFIG_INTEGER(config_look_prefix_align) == CONFIG_LOOK_PREFIX_ALIGN_RIGHT)
         {
@@ -595,9 +646,9 @@ gui_chat_display_time_and_prefix (struct t_gui_window *window,
         }
         
         prefix_highlighted = NULL;
-        if (line->highlight)
+        if (line->data->highlight)
         {
-            prefix_highlighted = gui_color_decode (line->prefix, NULL);
+            prefix_highlighted = gui_color_decode (line->data->prefix, NULL);
             if (!simulate)
             {
                 gui_window_set_weechat_color (GUI_WINDOW_OBJECTS(window)->win_chat,
@@ -610,19 +661,19 @@ gui_chat_display_time_and_prefix (struct t_gui_window *window,
             && (num_spaces < 0))
         {
             gui_chat_display_word (window, line,
-                                   (prefix_highlighted) ? prefix_highlighted : line->prefix,
+                                   (prefix_highlighted) ? prefix_highlighted : line->data->prefix,
                                    (prefix_highlighted) ?
                                    prefix_highlighted + gui_chat_string_real_pos (prefix_highlighted,
                                                                                   length_allowed) :
-                                   line->prefix + gui_chat_string_real_pos (line->prefix,
-                                                                            length_allowed),
+                                   line->data->prefix + gui_chat_string_real_pos (line->data->prefix,
+                                                                                  length_allowed),
                                    1, num_lines, count, lines_displayed,
                                    simulate);
         }
         else
         {
             gui_chat_display_word (window, line,
-                                   (prefix_highlighted) ? prefix_highlighted : line->prefix,
+                                   (prefix_highlighted) ? prefix_highlighted : line->data->prefix,
                                    NULL, 1, num_lines, count, lines_displayed,
                                    simulate);
         }
@@ -656,7 +707,7 @@ gui_chat_display_time_and_prefix (struct t_gui_window *window,
         }
         else
         {
-            if (window->buffer->prefix_max_length > 0)
+            if (window->buffer->lines->prefix_max_length > 0)
             {
                 gui_chat_display_word (window, line, str_space,
                                        NULL, 1, num_lines, count, lines_displayed,
@@ -728,8 +779,8 @@ gui_chat_display_line (struct t_gui_window *window, struct t_gui_line *line,
     }
     
     /* calculate marker position (maybe not used for this line!) */
-    if (window->buffer->time_for_each_line && line->str_time)
-        read_marker_x = x + gui_chat_strlen_screen (line->str_time);
+    if (window->buffer->time_for_each_line && line->data->str_time)
+        read_marker_x = x + gui_chat_strlen_screen (line->data->str_time);
     else
         read_marker_x = x;
     read_marker_y = y;
@@ -746,14 +797,14 @@ gui_chat_display_line (struct t_gui_window *window, struct t_gui_line *line,
     if (!simulate)
         gui_window_reset_style (GUI_WINDOW_OBJECTS(window)->win_chat, GUI_COLOR_CHAT);
     
-    if (!line->message || !line->message[0])
+    if (!line->data->message || !line->data->message[0])
     {
         gui_chat_display_new_line (window, num_lines, count,
                                    &lines_displayed, simulate);
     }
     else
     {
-        ptr_data = line->message;
+        ptr_data = line->data->message;
         while (ptr_data && ptr_data[0])
         {
             gui_chat_get_word_info (window,
@@ -767,7 +818,7 @@ gui_chat_display_line (struct t_gui_window *window, struct t_gui_line *line,
             if (word_length > 0)
             {
                 /* spaces + word too long for current line but ok for next line */
-                line_align = gui_chat_get_line_align (window->buffer, line, 1);
+                line_align = gui_line_get_align (window->buffer, line, 1);
                 if ((window->win_chat_cursor_x + word_length_with_spaces > gui_chat_get_real_width (window))
                     && (word_length <= gui_chat_get_real_width (window) - line_align))
                 {
@@ -830,7 +881,7 @@ gui_chat_display_line (struct t_gui_window *window, struct t_gui_line *line,
         }
     }
     
-    if (marker_line && gui_chat_get_next_line_displayed (line))
+    if (marker_line && gui_line_get_next_displayed (line))
     {
         gui_chat_display_horizontal_line (window, simulate);
         gui_chat_display_new_line (window, num_lines, count,
@@ -847,7 +898,7 @@ gui_chat_display_line (struct t_gui_window *window, struct t_gui_line *line,
         /* display marker if line is matching user search */
         if (window->buffer->text_search != GUI_TEXT_SEARCH_DISABLED)
         {
-            if (gui_chat_line_search (line, window->buffer->input_buffer,
+            if (gui_line_search_text (line, window->buffer->input_buffer,
                                       window->buffer->text_search_exact))
             {
                 gui_window_set_weechat_color (GUI_WINDOW_OBJECTS(window)->win_chat,
@@ -861,8 +912,8 @@ gui_chat_display_line (struct t_gui_window *window, struct t_gui_line *line,
         {
             /* display read marker if needed */
             if ((CONFIG_INTEGER(config_look_read_marker) == CONFIG_LOOK_READ_MARKER_CHAR)
-                && window->buffer->last_read_line
-                && (window->buffer->last_read_line == gui_chat_get_prev_line_displayed (line)))
+                && window->buffer->lines->last_read_line
+                && (window->buffer->lines->last_read_line == gui_line_get_prev_displayed (line)))
             {
                 gui_window_set_weechat_color (GUI_WINDOW_OBJECTS(window)->win_chat,
                                               GUI_COLOR_CHAT_READ_MARKER);
@@ -896,7 +947,7 @@ gui_chat_display_line_y (struct t_gui_window *window, struct t_gui_line *line,
            window->win_chat_cursor_x);
     wclrtoeol (GUI_WINDOW_OBJECTS(window)->win_chat);
     
-    if (gui_chat_display_word_raw (window, line->message,
+    if (gui_chat_display_word_raw (window, line->data->message,
                                    window->win_chat_width, 1) < window->win_chat_width)
     {
         gui_window_clrtoeol_with_current_bg (GUI_WINDOW_OBJECTS(window)->win_chat);
@@ -925,7 +976,7 @@ gui_chat_calculate_line_diff (struct t_gui_window *window,
         /* if looking backward, start at last line of buffer */
         if (backward)
         {
-            *line = gui_chat_get_last_line_displayed (window->buffer);
+            *line = gui_line_get_last_displayed (window->buffer);
             if (!(*line))
                 return;
             current_size = gui_chat_display_line (window, *line, 0, 1);
@@ -936,7 +987,7 @@ gui_chat_calculate_line_diff (struct t_gui_window *window,
         /* if looking forward, start at first line of buffer */
         else
         {
-            *line = gui_chat_get_first_line_displayed (window->buffer);
+            *line = gui_line_get_first_displayed (window->buffer);
             if (!(*line))
                 return;
             *line_pos = 0;
@@ -955,7 +1006,7 @@ gui_chat_calculate_line_diff (struct t_gui_window *window,
                 (*line_pos)--;
             else
             {
-                *line = gui_chat_get_prev_line_displayed (*line);
+                *line = gui_line_get_prev_displayed (*line);
                 if (*line)
                 {
                     current_size = gui_chat_display_line (window, *line, 0, 1);
@@ -973,7 +1024,7 @@ gui_chat_calculate_line_diff (struct t_gui_window *window,
                 (*line_pos)++;
             else
             {
-                *line = gui_chat_get_next_line_displayed (*line);
+                *line = gui_line_get_next_displayed (*line);
                 if (*line)
                 {
                     current_size = gui_chat_display_line (window, *line, 0, 1);
@@ -992,7 +1043,7 @@ gui_chat_calculate_line_diff (struct t_gui_window *window,
         if (backward)
         {
             /* first line reached */
-            *line = gui_chat_get_first_line_displayed (window->buffer);
+            *line = gui_line_get_first_displayed (window->buffer);
             *line_pos = 0;
         }
         else
@@ -1020,7 +1071,7 @@ gui_chat_draw (struct t_gui_buffer *buffer, int erase)
     
     for (ptr_win = gui_windows; ptr_win; ptr_win = ptr_win->next_window)
     {
-        if (ptr_win->buffer == buffer)
+        if (ptr_win->buffer->number == buffer->number)
         {
             if (erase)
             {
@@ -1069,18 +1120,18 @@ gui_chat_draw (struct t_gui_buffer *buffer, int erase)
                                                                               ptr_line,
                                                                               0, 1) -
                                                        line_pos, 0);
-                        ptr_line = gui_chat_get_next_line_displayed (ptr_line);
+                        ptr_line = gui_line_get_next_displayed (ptr_line);
                         ptr_win->first_line_displayed = 0;
                     }
                     else
                         ptr_win->first_line_displayed =
-                            (ptr_line == gui_chat_get_first_line_displayed (ptr_win->buffer));
+                            (ptr_line == gui_line_get_first_displayed (ptr_win->buffer));
                     
                     /* display lines */
                     while (ptr_line && (ptr_win->win_chat_cursor_y <= ptr_win->win_chat_height - 1))
                     {
                         count = gui_chat_display_line (ptr_win, ptr_line, 0, 0);
-                        ptr_line = gui_chat_get_next_line_displayed (ptr_line);
+                        ptr_line = gui_line_get_next_displayed (ptr_line);
                     }
                     
                     old_scroll = ptr_win->scroll;
@@ -1092,13 +1143,13 @@ gui_chat_draw (struct t_gui_buffer *buffer, int erase)
                     /* if so, disable scroll indicator */
                     if (!ptr_line && ptr_win->scroll)
                     {
-                        if ((count == gui_chat_display_line (ptr_win, gui_chat_get_last_line_displayed (ptr_win->buffer), 0, 1))
+                        if ((count == gui_chat_display_line (ptr_win, gui_line_get_last_displayed (ptr_win->buffer), 0, 1))
                             || (count == ptr_win->win_chat_height))
                             ptr_win->scroll = 0;
                     }
                     
                     if (!ptr_win->scroll
-                        && (ptr_win->start_line == gui_chat_get_first_line_displayed (ptr_win->buffer)))
+                        && (ptr_win->start_line == gui_line_get_first_displayed (ptr_win->buffer)))
                     {
                         ptr_win->start_line = NULL;
                         ptr_win->start_line_pos = 0;
@@ -1110,7 +1161,7 @@ gui_chat_draw (struct t_gui_buffer *buffer, int erase)
                         /* count number of lines after last line displayed */
                         while (ptr_line)
                         {
-                            ptr_line = gui_chat_get_next_line_displayed (ptr_line);
+                            ptr_line = gui_line_get_next_displayed (ptr_line);
                             if (ptr_line)
                                 ptr_win->scroll_lines_after++;
                         }
@@ -1144,23 +1195,23 @@ gui_chat_draw (struct t_gui_buffer *buffer, int erase)
                 case GUI_BUFFER_TYPE_FREE:
                     /* display at position of scrolling */
                     ptr_line = (ptr_win->start_line) ?
-                        ptr_win->start_line : buffer->lines;
+                        ptr_win->start_line : buffer->lines->first_line;
                     if (ptr_line)
                     {
-                        if (!ptr_line->displayed)
-                            ptr_line = gui_chat_get_next_line_displayed (ptr_line);
+                        if (!ptr_line->data->displayed)
+                            ptr_line = gui_line_get_next_displayed (ptr_line);
                         if (ptr_line)
                         {
-                            y_start = (ptr_win->start_line) ? ptr_line->y : 0;
+                            y_start = (ptr_win->start_line) ? ptr_line->data->y : 0;
                             y_end = y_start + ptr_win->win_chat_height - 1;
-                            while (ptr_line && (ptr_line->y <= y_end))
+                            while (ptr_line && (ptr_line->data->y <= y_end))
                             {
-                                if (ptr_line->refresh_needed || erase)
+                                if (ptr_line->data->refresh_needed || erase)
                                 {
                                     gui_chat_display_line_y (ptr_win, ptr_line,
-                                                             ptr_line->y - y_start);
+                                                             ptr_line->data->y - y_start);
                                 }
-                                ptr_line = gui_chat_get_next_line_displayed (ptr_line);
+                                ptr_line = gui_line_get_next_displayed (ptr_line);
                             }
                         }
                     }
@@ -1176,10 +1227,10 @@ gui_chat_draw (struct t_gui_buffer *buffer, int erase)
     
     if (buffer->type == GUI_BUFFER_TYPE_FREE)
     {
-        for (ptr_line = buffer->lines; ptr_line;
+        for (ptr_line = buffer->lines->first_line; ptr_line;
              ptr_line = ptr_line->next_line)
         {
-            ptr_line->refresh_needed = 0;
+            ptr_line->data->refresh_needed = 0;
         }
     }
     
diff --git a/src/gui/curses/gui-curses-color.c b/src/gui/curses/gui-curses-color.c
index 1403e5e69..914713c61 100644
--- a/src/gui/curses/gui-curses-color.c
+++ b/src/gui/curses/gui-curses-color.c
@@ -382,6 +382,7 @@ gui_color_init_weechat ()
     gui_color_build (GUI_COLOR_CHAT_READ_MARKER, CONFIG_COLOR(config_color_chat_read_marker), CONFIG_COLOR(config_color_chat_read_marker_bg));
     gui_color_build (GUI_COLOR_CHAT_TEXT_FOUND, CONFIG_COLOR(config_color_chat_text_found), CONFIG_COLOR(config_color_chat_text_found_bg));
     gui_color_build (GUI_COLOR_CHAT_VALUE, CONFIG_COLOR(config_color_chat_value), CONFIG_COLOR(config_color_chat_bg));
+    gui_color_build (GUI_COLOR_CHAT_PREFIX_BUFFER, CONFIG_COLOR(config_color_chat_prefix_buffer), CONFIG_COLOR(config_color_chat_bg));
 }
 
 /*
diff --git a/src/gui/curses/gui-curses-keyboard.c b/src/gui/curses/gui-curses-keyboard.c
index e19365c49..d7d1e6a4e 100644
--- a/src/gui/curses/gui-curses-keyboard.c
+++ b/src/gui/curses/gui-curses-keyboard.c
@@ -86,6 +86,7 @@ gui_keyboard_default_bindings ()
     gui_keyboard_default_bind (/* del           */ "meta2-3~",           "/input delete_next_char");
     gui_keyboard_default_bind (/* ^D            */ "ctrl-D",             "/input delete_next_char");
     gui_keyboard_default_bind (/* ^W            */ "ctrl-W",             "/input delete_previous_word");
+    gui_keyboard_default_bind (/* ^X            */ "ctrl-X",             "/input switch_active_buffer");
     gui_keyboard_default_bind (/* m-d           */ "meta-d",             "/input delete_next_word");
     gui_keyboard_default_bind (/* ^K            */ "ctrl-K",             "/input delete_end_of_line");
     gui_keyboard_default_bind (/* m-r           */ "meta-r",             "/input delete_line");
@@ -114,16 +115,14 @@ gui_keyboard_default_bindings ()
     gui_keyboard_default_bind (/* ^down         */ "meta-Ob",            "/input history_global_next");
     gui_keyboard_default_bind (/* m-a           */ "meta-a",             "/input jump_smart");
     gui_keyboard_default_bind (/* m-j,m-l       */ "meta-jmeta-l",       "/input jump_last_buffer");
-    gui_keyboard_default_bind (/* m-j,m-p       */ "meta-jmeta-p",       "/input jump_previous_buffer");
     gui_keyboard_default_bind (/* m-j,m-r       */ "meta-jmeta-r",       "/server raw");
     gui_keyboard_default_bind (/* m-h           */ "meta-h",             "/input hotlist_clear");
     gui_keyboard_default_bind (/* m-k           */ "meta-k",             "/input grab_key");
-    gui_keyboard_default_bind (/* m-s           */ "meta-s",             "/server switch");
     gui_keyboard_default_bind (/* m-u           */ "meta-u",             "/input scroll_unread");
     gui_keyboard_default_bind (/* ^S^U          */ "ctrl-Sctrl-U",       "/input set_unread");
     gui_keyboard_default_bind (/* ^Cb           */ "ctrl-Cb",            "/input insert \\x02");
     gui_keyboard_default_bind (/* ^Cc           */ "ctrl-Cc",            "/input insert \\x03");
-    gui_keyboard_default_bind (/* ^Cc           */ "ctrl-Ci",            "/input insert \\x1D");
+    gui_keyboard_default_bind (/* ^Ci           */ "ctrl-Ci",            "/input insert \\x1D");
     gui_keyboard_default_bind (/* ^Co           */ "ctrl-Co",            "/input insert \\x0F");
     gui_keyboard_default_bind (/* ^Cr           */ "ctrl-Cr",            "/input insert \\x12");
     gui_keyboard_default_bind (/* ^Cu           */ "ctrl-Cu",            "/input insert \\x15");
diff --git a/src/gui/curses/gui-curses-window.c b/src/gui/curses/gui-curses-window.c
index 5bf42f16b..7c20cc1a6 100644
--- a/src/gui/curses/gui-curses-window.c
+++ b/src/gui/curses/gui-curses-window.c
@@ -43,6 +43,7 @@
 #include "../gui-hotlist.h"
 #include "../gui-input.h"
 #include "../gui-main.h"
+#include "../gui-line.h"
 #include "../gui-nicklist.h"
 #include "gui-curses.h"
 
@@ -488,12 +489,11 @@ gui_window_switch_to_buffer (struct t_gui_window *window,
     if (!gui_ok)
         return;
     
-    if (window->buffer->num_displayed > 0)
-        window->buffer->num_displayed--;
+    gui_buffer_add_value_num_displayed (window->buffer, -1);
     
     old_buffer = window->buffer;
     
-    if (window->buffer != buffer)
+    if (window->buffer->number != buffer->number)
     {
         window->start_line = NULL;
         window->start_line_pos = 0;
@@ -506,19 +506,19 @@ gui_window_switch_to_buffer (struct t_gui_window *window,
         {
             if (window->buffer->num_displayed == 0)
             {
-                window->buffer->last_read_line = window->buffer->last_line;
-                window->buffer->first_line_not_read = 0;
+                window->buffer->lines->last_read_line = window->buffer->lines->last_line;
+                window->buffer->lines->first_line_not_read = 0;
             }
-            if (buffer->last_read_line == buffer->last_line)
+            if (buffer->lines->last_read_line == buffer->lines->last_line)
             {
-                buffer->last_read_line = NULL;
-                buffer->first_line_not_read = 0;
+                buffer->lines->last_read_line = NULL;
+                buffer->lines->first_line_not_read = 0;
             }
         }
     }
     
     window->buffer = buffer;
-    buffer->num_displayed++;
+    gui_buffer_add_value_num_displayed (buffer, 1);
     
     gui_hotlist_remove_buffer (buffer);
     
@@ -558,6 +558,8 @@ gui_window_switch_to_buffer (struct t_gui_window *window,
         window->scroll_lines_after = 0;
     }
     
+    gui_buffer_set_active_buffer (buffer);
+    
     for (ptr_bar_window = window->bar_windows; ptr_bar_window;
          ptr_bar_window = ptr_bar_window->next_bar_window)
     {
@@ -812,7 +814,7 @@ gui_window_scroll_top (struct t_gui_window *window)
         case GUI_BUFFER_TYPE_FORMATTED:
             if (!window->first_line_displayed)
             {
-                window->start_line = gui_chat_get_first_line_displayed (window->buffer);
+                window->start_line = gui_line_get_first_displayed (window->buffer);
                 window->start_line_pos = 0;
                 window->scroll_reset_allowed = 1;
                 gui_buffer_ask_chat_refresh (window->buffer, 2);
@@ -857,7 +859,7 @@ gui_window_scroll_bottom (struct t_gui_window *window)
             break;
         case GUI_BUFFER_TYPE_FREE:
             window->start_line = NULL;
-            if (window->buffer->lines_count > window->win_chat_height)
+            if (window->buffer->lines->lines_count > window->win_chat_height)
             {
                 snprintf (scroll, sizeof (scroll), "-%d",
                           window->win_chat_height - 1);
@@ -1015,7 +1017,7 @@ gui_window_split_horizontal (struct t_gui_window *window, int percentage)
             window->win_height_pct = 100 - percentage;
             
             /* assign same buffer for new window (top window) */
-            new_window->buffer->num_displayed++;
+            gui_buffer_add_value_num_displayed (new_window->buffer, 1);
             
             window->refresh_needed = 1;
             new_window->refresh_needed = 1;
@@ -1059,7 +1061,7 @@ gui_window_split_vertical (struct t_gui_window *window, int percentage)
             window->win_width_pct = 100 - percentage;
             
             /* assign same buffer for new window (right window) */
-            new_window->buffer->num_displayed++;
+            gui_buffer_add_value_num_displayed (new_window->buffer, 1);
             
             window->refresh_needed = 1;
             new_window->refresh_needed = 1;
diff --git a/src/gui/gtk/gui-gtk-bar-window.c b/src/gui/gtk/gui-gtk-bar-window.c
index a7eacbd4f..95a6e9850 100644
--- a/src/gui/gtk/gui-gtk-bar-window.c
+++ b/src/gui/gtk/gui-gtk-bar-window.c
@@ -30,7 +30,6 @@
 #include "../../core/wee-log.h"
 #include "../gui-bar.h"
 #include "../gui-bar-window.h"
-#include "../gui-chat.h"
 #include "../gui-color.h"
 #include "../gui-window.h"
 #include "gui-gtk.h"
diff --git a/src/gui/gtk/gui-gtk-chat.c b/src/gui/gtk/gui-gtk-chat.c
index 7b009f83c..2cdd395a7 100644
--- a/src/gui/gtk/gui-gtk-chat.c
+++ b/src/gui/gtk/gui-gtk-chat.c
@@ -34,6 +34,7 @@
 #include "../gui-chat.h"
 #include "../gui-color.h"
 #include "../gui-main.h"
+#include "../gui-line.h"
 #include "../gui-window.h"
 #include "gui-gtk.h"
 
@@ -358,7 +359,7 @@ gui_chat_calculate_line_diff (struct t_gui_window *window, struct t_gui_line **l
         /* if looking backward, start at last line of buffer */
         if (backward)
         {
-            *line = window->buffer->last_line;
+            *line = window->buffer->lines->last_line;
             if (!(*line))
                 return;
             current_size = gui_chat_display_line (window, *line, 0, 1);
@@ -369,7 +370,7 @@ gui_chat_calculate_line_diff (struct t_gui_window *window, struct t_gui_line **l
         /* if looking forward, start at first line of buffer */
         else
         {
-            *line = window->buffer->lines;
+            *line = window->buffer->lines->first_line;
             if (!(*line))
                 return;
             *line_pos = 0;
@@ -425,7 +426,7 @@ gui_chat_calculate_line_diff (struct t_gui_window *window, struct t_gui_line **l
         if (backward)
         {
             /* first line reached */
-            *line = window->buffer->lines;
+            *line = window->buffer->lines->first_line;
             *line_pos = 0;
         }
         else
diff --git a/src/gui/gtk/gui-gtk-color.c b/src/gui/gtk/gui-gtk-color.c
index c40c342aa..b25e7baed 100644
--- a/src/gui/gtk/gui-gtk-color.c
+++ b/src/gui/gtk/gui-gtk-color.c
@@ -31,7 +31,6 @@
 #include "../../core/wee-config.h"
 #include "../../core/wee-string.h"
 #include "../gui-color.h"
-#include "../gui-chat.h"
 #include "gui-gtk.h"
 
 
diff --git a/src/gui/gtk/gui-gtk-window.c b/src/gui/gtk/gui-gtk-window.c
index ecb836257..2d64dddfe 100644
--- a/src/gui/gtk/gui-gtk-window.c
+++ b/src/gui/gtk/gui-gtk-window.c
@@ -34,6 +34,7 @@
 #include "../gui-buffer.h"
 #include "../gui-chat.h"
 #include "../gui-hotlist.h"
+#include "../gui-line.h"
 #include "../gui-nicklist.h"
 #include "../gui-main.h"
 #include "gui-gtk.h"
@@ -195,8 +196,7 @@ gui_window_switch_to_buffer (struct t_gui_window *window,
 {
     GtkTextIter start, end;
     
-    if (window->buffer->num_displayed > 0)
-        window->buffer->num_displayed--;
+    gui_buffer_add_value_num_displayed (window->buffer, -1);
     
     if (window->buffer != buffer)
     {
@@ -211,13 +211,13 @@ gui_window_switch_to_buffer (struct t_gui_window *window,
         {
             if (window->buffer->num_displayed == 0)
             {
-                window->buffer->last_read_line = window->buffer->last_line;
-                window->buffer->first_line_not_read = 0;
+                window->buffer->lines->last_read_line = window->buffer->lines->last_line;
+                window->buffer->lines->first_line_not_read = 0;
             }
-            if (buffer->last_read_line == buffer->last_line)
+            if (buffer->lines->last_read_line == buffer->lines->last_line)
             {
-                buffer->last_read_line = NULL;
-                buffer->first_line_not_read = 0;
+                buffer->lines->last_read_line = NULL;
+                buffer->lines->first_line_not_read = 0;
             }
         }
     }
@@ -245,7 +245,7 @@ gui_window_switch_to_buffer (struct t_gui_window *window,
     window->start_line = NULL;
     window->start_line_pos = 0;
     
-    buffer->num_displayed++;
+    gui_buffer_add_value_num_displayed (buffer, 1);
     
     gui_hotlist_remove_buffer (buffer);
 }
@@ -376,7 +376,7 @@ gui_window_scroll_top (struct t_gui_window *window)
     
     if (!window->first_line_displayed)
     {
-        window->start_line = window->buffer->lines;
+        window->start_line = window->buffer->lines->first_line;
         window->start_line_pos = 0;
         gui_chat_draw (window->buffer, 0);
     }
@@ -502,7 +502,7 @@ gui_window_split_horizontal (struct t_gui_window *window, int percentage)
             window->win_height_pct = 100 - percentage;
             
             /* assign same buffer for new window (top window) */
-            new_window->buffer->num_displayed++;
+            gui_buffer_add_value_num_displayed (new_window->buffer, 1);
             
             gui_window_switch_to_buffer (window, window->buffer, 1);
             
@@ -546,7 +546,7 @@ gui_window_split_vertical (struct t_gui_window *window, int percentage)
             window->win_width_pct = 100 - percentage;
             
             /* assign same buffer for new window (right window) */
-            new_window->buffer->num_displayed++;
+            gui_buffer_add_value_num_displayed (new_window->buffer, 1);
             
             gui_window_switch_to_buffer (window, window->buffer, 1);
             
diff --git a/src/gui/gui-bar-item.c b/src/gui/gui-bar-item.c
index f78dcea16..73a233db6 100644
--- a/src/gui/gui-bar-item.c
+++ b/src/gui/gui-bar-item.c
@@ -45,6 +45,7 @@
 #include "gui-filter.h"
 #include "gui-hotlist.h"
 #include "gui-keyboard.h"
+#include "gui-line.h"
 #include "gui-nicklist.h"
 #include "gui-window.h"
 
@@ -881,7 +882,7 @@ gui_bar_item_default_buffer_filter (void *data, struct t_gui_bar_item *item,
     if (!window)
         window = gui_current_window;
     
-    if (!gui_filters_enabled || !gui_filters || !window->buffer->lines_hidden)
+    if (!gui_filters_enabled || !gui_filters || !window->buffer->lines->lines_hidden)
         return NULL;
     
     snprintf (buf, sizeof (buf),
@@ -1366,6 +1367,10 @@ gui_bar_item_init ()
                               gui_bar_item_names[GUI_BAR_ITEM_BUFFER_NUMBER]);
     gui_bar_item_hook_signal ("buffer_moved",
                               gui_bar_item_names[GUI_BAR_ITEM_BUFFER_NUMBER]);
+    gui_bar_item_hook_signal ("buffer_merged",
+                              gui_bar_item_names[GUI_BAR_ITEM_BUFFER_NUMBER]);
+    gui_bar_item_hook_signal ("buffer_unmerged",
+                              gui_bar_item_names[GUI_BAR_ITEM_BUFFER_NUMBER]);
     
     /* buffer name */
     gui_bar_item_new (NULL,
diff --git a/src/gui/gui-buffer.c b/src/gui/gui-buffer.c
index e933e48ef..373451276 100644
--- a/src/gui/gui-buffer.c
+++ b/src/gui/gui-buffer.c
@@ -49,6 +49,7 @@
 #include "gui-input.h"
 #include "gui-keyboard.h"
 #include "gui-layout.h"
+#include "gui-line.h"
 #include "gui-main.h"
 #include "gui-nicklist.h"
 #include "gui-window.h"
@@ -394,6 +395,8 @@ gui_buffer_new (struct t_weechat_plugin *plugin,
         /* init buffer */
         new_buffer->plugin = plugin;
         new_buffer->plugin_name_for_upgrade = NULL;
+        new_buffer->merge_for_upgrade = NULL;
+        
         /* number will be set later (when inserting buffer in list) */
         new_buffer->layout_number = gui_layout_buffer_get_number (gui_layout_buffers,
                                                                   plugin_get_name (plugin),
@@ -403,6 +406,7 @@ gui_buffer_new (struct t_weechat_plugin *plugin,
         new_buffer->type = GUI_BUFFER_TYPE_FORMATTED;
         new_buffer->notify = CONFIG_INTEGER(config_look_buffer_notify_default);
         new_buffer->num_displayed = 0;
+        new_buffer->active = 1;
         new_buffer->print_hooks_enabled = 1;
         
         /* close callback */
@@ -412,14 +416,10 @@ gui_buffer_new (struct t_weechat_plugin *plugin,
         /* title */
         new_buffer->title = NULL;
         
-        /* chat lines (formatted) */
-        new_buffer->lines = NULL;
-        new_buffer->last_line = NULL;
-        new_buffer->last_read_line = NULL;
-        new_buffer->first_line_not_read = 0;
-        new_buffer->lines_count = 0;
-        new_buffer->lines_hidden = 0;
-        new_buffer->prefix_max_length = 0;
+        /* chat content */
+        new_buffer->own_lines = gui_lines_alloc ();
+        new_buffer->mixed_lines = NULL;
+        new_buffer->lines = new_buffer->own_lines;
         new_buffer->time_for_each_line = 1;
         new_buffer->chat_refresh_needed = 2;
         
@@ -653,9 +653,9 @@ gui_buffer_get_integer (struct t_gui_buffer *buffer, const char *property)
         else if (string_strcasecmp (property, "notify") == 0)
             return buffer->notify;
         else if (string_strcasecmp (property, "lines_hidden") == 0)
-            return buffer->lines_hidden;
+            return buffer->lines->lines_hidden;
         else if (string_strcasecmp (property, "prefix_max_length") == 0)
-            return buffer->prefix_max_length;
+            return buffer->lines->prefix_max_length;
         else if (string_strcasecmp (property, "time_for_each_line") == 0)
             return buffer->time_for_each_line;
         else if (string_strcasecmp (property, "text_search") == 0)
@@ -776,7 +776,7 @@ gui_buffer_set_type (struct t_gui_buffer *buffer, enum t_gui_buffer_type type)
     if (buffer->type == type)
         return;
     
-    gui_chat_line_free_all (buffer);
+    gui_line_free_all (buffer);
     
     buffer->type = type;
     gui_buffer_ask_chat_refresh (buffer, 2);
@@ -915,11 +915,11 @@ gui_buffer_set_unread (struct t_gui_buffer *buffer)
 
     if (buffer->type == GUI_BUFFER_TYPE_FORMATTED)
     {
-        refresh = ((buffer->last_read_line != NULL)
-                   && (buffer->last_read_line != buffer->last_line));
+        refresh = ((buffer->lines->last_read_line != NULL)
+                   && (buffer->lines->last_read_line != buffer->lines->last_line));
         
-        buffer->last_read_line = buffer->last_line;
-        buffer->first_line_not_read = (buffer->last_read_line) ? 0 : 1;
+        buffer->lines->last_read_line = buffer->lines->last_line;
+        buffer->lines->first_line_not_read = (buffer->lines->last_read_line) ? 0 : 1;
         
         if (refresh)
             gui_buffer_ask_chat_refresh (buffer, 2);
@@ -1116,6 +1116,28 @@ gui_buffer_set_pointer (struct t_gui_buffer *buffer, const char *property,
 }
 
 /*
+ * gui_buffer_add_value_num_displayed: add value to "num_displayed" variable
+ *                                     for a buffer (value can be negative)
+ */
+
+void
+gui_buffer_add_value_num_displayed (struct t_gui_buffer *buffer, int value)
+{
+    struct t_gui_buffer *ptr_buffer;
+    
+    for (ptr_buffer = gui_buffers; ptr_buffer;
+         ptr_buffer = ptr_buffer->next_buffer)
+    {
+        if (ptr_buffer->number == buffer->number)
+        {
+            ptr_buffer->num_displayed += value;
+            if (ptr_buffer->num_displayed < 0)
+                ptr_buffer->num_displayed = 0;
+        }
+    }
+}
+
+/*
  * gui_buffer_search_main: get main buffer (weechat one, created at startup)
  *                         return first buffer if not found
  */
@@ -1132,8 +1154,8 @@ gui_buffer_search_main ()
             return ptr_buffer;
     }
     
-    /* buffer not found, return first buffer by default */
-    return gui_buffers;
+    /* buffer not found (should never occur!) */
+    return NULL;
 }
 
 /*
@@ -1298,6 +1320,29 @@ gui_buffer_search_by_number (int number)
 }
 
 /*
+ * gui_buffer_count_merged_buffers: return number of merged buffers (buffers
+ *                                  with same number)
+ */
+
+int
+gui_buffer_count_merged_buffers (int number)
+{
+    struct t_gui_buffer *ptr_buffer;
+    int count;
+    
+    count = 0;
+    
+    for (ptr_buffer = gui_buffers; ptr_buffer;
+         ptr_buffer = ptr_buffer->next_buffer)
+    {
+        if (ptr_buffer->number == number)
+            count++;
+    }
+    
+    return count;
+}
+
+/*
  * gui_buffer_is_scrolled: return 1 if all windows displaying buffer are scrolled
  *                         (user doesn't see end of buffer)
  *                         return 0 if at least one window is NOT scrolled
@@ -1345,7 +1390,7 @@ gui_buffer_clear (struct t_gui_buffer *buffer)
         return;
     
     /* remove all lines */
-    gui_chat_line_free_all (buffer);
+    gui_line_free_all (buffer);
     
     /* remove any scroll for buffer */
     for (ptr_win = gui_windows; ptr_win; ptr_win = ptr_win->next_window)
@@ -1397,6 +1442,10 @@ gui_buffer_close (struct t_gui_buffer *buffer)
     {
         (void)(buffer->close_callback) (buffer->close_callback_data, buffer);
     }
+
+    /* first unmerge buffer if it is merged to at least one other buffer */
+    if (gui_buffer_count_merged_buffers (buffer->number) > 1)
+        gui_buffer_unmerge (buffer, -1);
     
     if (!weechat_quit)
     {
@@ -1465,7 +1514,7 @@ gui_buffer_close (struct t_gui_buffer *buffer)
     }
     
     /* free all lines */
-    gui_chat_line_free_all (buffer);
+    gui_line_free_all (buffer);
     
     /* free some data */
     if (buffer->title)
@@ -1531,7 +1580,8 @@ gui_buffer_switch_by_number (struct t_gui_window *window, int number)
     /* search for buffer in the list */
     for (ptr_buffer = gui_buffers; ptr_buffer; ptr_buffer = ptr_buffer->next_buffer)
     {
-        if ((ptr_buffer != window->buffer) && (number == ptr_buffer->number))
+        if ((ptr_buffer != window->buffer) && (number == ptr_buffer->number)
+            && ptr_buffer->active)
         {
             gui_window_switch_to_buffer (window, ptr_buffer, 1);
             return;
@@ -1540,14 +1590,60 @@ gui_buffer_switch_by_number (struct t_gui_window *window, int number)
 }
 
 /*
+ * gui_buffer_set_active_buffer: set active buffer (when many buffers are
+ *                               merged)
+ */
+
+void
+gui_buffer_set_active_buffer (struct t_gui_buffer *buffer)
+{
+    struct t_gui_buffer *ptr_buffer;
+    
+    for (ptr_buffer = gui_buffers; ptr_buffer;
+         ptr_buffer = ptr_buffer->next_buffer)
+    {
+        if (ptr_buffer->number == buffer->number)
+            ptr_buffer->active = (ptr_buffer == buffer) ? 1 : 0;
+    }
+}
+
+/*
+ * gui_buffer_get_next_active_buffer: get next active buffer (when many buffers
+ *                                    are merged)
+ */
+
+struct t_gui_buffer *
+gui_buffer_get_next_active_buffer (struct t_gui_buffer *buffer)
+{
+    struct t_gui_buffer *ptr_buffer;
+    
+    if (buffer->next_buffer
+        && (buffer->next_buffer->number == buffer->number))
+        return buffer->next_buffer;
+    else
+    {
+        for (ptr_buffer = gui_buffers; ptr_buffer;
+             ptr_buffer = ptr_buffer->next_buffer)
+        {
+            if ((ptr_buffer != buffer)
+                && (ptr_buffer->number == buffer->number))
+            {
+                return ptr_buffer;
+            }
+        }
+    }
+    return buffer;
+}
+
+/*
  * gui_buffer_move_to_number: move a buffer to another number
  */
 
 void
 gui_buffer_move_to_number (struct t_gui_buffer *buffer, int number)
 {
-    struct t_gui_buffer *ptr_buffer;
-    int i;
+    struct t_gui_buffer *ptr_first_buffer, *ptr_last_buffer, *ptr_buffer;
+    struct t_gui_buffer *ptr_buffer_pos;
     char buf1_str[16], buf2_str[16], *argv[2] = { NULL, NULL };
     
     /* if only one buffer then return */
@@ -1561,26 +1657,61 @@ gui_buffer_move_to_number (struct t_gui_buffer *buffer, int number)
     if (number == buffer->number)
         return;
     
+    ptr_first_buffer = NULL;
+    ptr_last_buffer = NULL;
+    for (ptr_buffer = gui_buffers; ptr_buffer;
+         ptr_buffer = ptr_buffer->next_buffer)
+    {
+        if (ptr_buffer->number == buffer->number)
+        {
+            if (!ptr_first_buffer)
+                ptr_first_buffer = ptr_buffer;
+            ptr_last_buffer = ptr_buffer;
+        }
+    }
+    
+    /* error when looking for buffers */
+    if (!ptr_first_buffer || !ptr_last_buffer)
+        return;
+    
+    /* if group of buffers found is all buffers, then we can't move buffers! */
+    if ((ptr_first_buffer == gui_buffers) && (ptr_last_buffer == last_gui_buffer))
+        return;
+    
     snprintf (buf2_str, sizeof (buf2_str) - 1, "%d", buffer->number);
     
-    /* remove buffer from list */
-    if (buffer == gui_buffers)
+    /* remove buffer(s) from list */
+    if (ptr_first_buffer == gui_buffers)
     {
-        gui_buffers = buffer->next_buffer;
+        gui_buffers = ptr_last_buffer->next_buffer;
         gui_buffers->prev_buffer = NULL;
     }
-    if (buffer == last_gui_buffer)
+    else if (ptr_last_buffer == last_gui_buffer)
     {
-        last_gui_buffer = buffer->prev_buffer;
+        last_gui_buffer = ptr_first_buffer->prev_buffer;
         last_gui_buffer->next_buffer = NULL;
     }
-    if (buffer->prev_buffer)
-        (buffer->prev_buffer)->next_buffer = buffer->next_buffer;
-    if (buffer->next_buffer)
-        (buffer->next_buffer)->prev_buffer = buffer->prev_buffer;
+    if (ptr_first_buffer->prev_buffer)
+        (ptr_first_buffer->prev_buffer)->next_buffer = ptr_last_buffer->next_buffer;
+    if (ptr_last_buffer->next_buffer)
+        (ptr_last_buffer->next_buffer)->prev_buffer = ptr_first_buffer->prev_buffer;
+    
+    /* compute "number - 1" for all buffers after buffer(s) */
+    for (ptr_buffer = ptr_last_buffer->next_buffer; ptr_buffer;
+         ptr_buffer = ptr_buffer->next_buffer)
+    {
+        ptr_buffer->number--;
+    }
     
     if (number == 1)
     {
+        for (ptr_buffer = ptr_first_buffer; ptr_buffer;
+             ptr_buffer = ptr_buffer->next_buffer)
+        {
+            ptr_buffer->number = 1;
+            if (ptr_buffer == ptr_last_buffer)
+                break;
+        }
         gui_buffers->prev_buffer = buffer;
         buffer->prev_buffer = NULL;
         buffer->next_buffer = gui_buffers;
@@ -1588,43 +1719,51 @@ gui_buffer_move_to_number (struct t_gui_buffer *buffer, int number)
     }
     else
     {
-        /* assign new number to all buffers */
-        i = 1;
-        for (ptr_buffer = gui_buffers; ptr_buffer; ptr_buffer = ptr_buffer->next_buffer)
-        {
-            ptr_buffer->number = i++;
-        }
-        
         /* search for new position in the list */
-        for (ptr_buffer = gui_buffers; ptr_buffer; ptr_buffer = ptr_buffer->next_buffer)
+        for (ptr_buffer_pos = gui_buffers; ptr_buffer_pos;
+             ptr_buffer_pos = ptr_buffer_pos->next_buffer)
         {
-            if (ptr_buffer->number == number)
+            if (ptr_buffer_pos->number == number)
                 break;
         }
-        if (ptr_buffer)
+        if (ptr_buffer_pos)
         {
             /* insert before buffer found */
-            buffer->prev_buffer = ptr_buffer->prev_buffer;
-            buffer->next_buffer = ptr_buffer;
-            if (ptr_buffer->prev_buffer)
-                (ptr_buffer->prev_buffer)->next_buffer = buffer;
-            ptr_buffer->prev_buffer = buffer;
+            for (ptr_buffer = ptr_first_buffer; ptr_buffer;
+                 ptr_buffer = ptr_buffer->next_buffer)
+            {
+                ptr_buffer->number = ptr_buffer_pos->number;
+                if (ptr_buffer == ptr_last_buffer)
+                    break;
+            }
+            ptr_first_buffer->prev_buffer = ptr_buffer_pos->prev_buffer;
+            ptr_last_buffer->next_buffer = ptr_buffer_pos;
+            if (ptr_buffer_pos->prev_buffer)
+                (ptr_buffer_pos->prev_buffer)->next_buffer = ptr_first_buffer;
+            ptr_buffer_pos->prev_buffer = ptr_last_buffer;
         }
         else
         {
             /* number not found (too big)? => add to end */
-            buffer->prev_buffer = last_gui_buffer;
-            buffer->next_buffer = NULL;
-            last_gui_buffer->next_buffer = buffer;
-            last_gui_buffer = buffer;
+            for (ptr_buffer = ptr_first_buffer; ptr_buffer;
+                 ptr_buffer = ptr_buffer->next_buffer)
+            {
+                ptr_buffer->number = last_gui_buffer->number + 1;
+                if (ptr_buffer == ptr_last_buffer)
+                    break;
+            }
+            ptr_first_buffer->prev_buffer = last_gui_buffer;
+            ptr_last_buffer->next_buffer = NULL;
+            last_gui_buffer->next_buffer = ptr_first_buffer;
+            last_gui_buffer = ptr_last_buffer;
         }
     }
     
-    /* assign new number to all buffers */
-    i = 1;
-    for (ptr_buffer = gui_buffers; ptr_buffer; ptr_buffer = ptr_buffer->next_buffer)
+    /* compute "number + 1" for all buffers after buffer(s) */
+    for (ptr_buffer = ptr_last_buffer->next_buffer; ptr_buffer;
+         ptr_buffer = ptr_buffer->next_buffer)
     {
-        ptr_buffer->number = i++;
+        ptr_buffer->number++;
     }
     
     snprintf (buf1_str, sizeof (buf1_str) - 1, "%d", buffer->number);
@@ -1636,6 +1775,176 @@ gui_buffer_move_to_number (struct t_gui_buffer *buffer, int number)
 }
 
 /*
+ * gui_buffer_merge: merge a buffer to another buffer
+ */
+
+void
+gui_buffer_merge (struct t_gui_buffer *buffer,
+                  struct t_gui_buffer *target_buffer)
+{
+    struct t_gui_buffer *ptr_buffer;
+    int target_number;
+    
+    /* if only one buffer then return */
+    if (gui_buffers == last_gui_buffer)
+        return;
+    
+    if ((buffer == target_buffer) || (buffer->number == target_buffer->number))
+        return;
+    
+    if (gui_buffer_count_merged_buffers (buffer->number) > 1)
+        gui_buffer_unmerge (buffer, -1);
+    
+    /* check if current buffer and target buffers are type "formatted" */
+    if ((buffer->type != GUI_BUFFER_TYPE_FORMATTED)
+        || (target_buffer->type != GUI_BUFFER_TYPE_FORMATTED))
+    {
+        gui_chat_printf (NULL,
+                         _("%sError: it is only possible to merge buffers "
+                           "with formatted content"),
+                         gui_chat_prefix[GUI_CHAT_PREFIX_ERROR]);
+        return;
+    }
+    
+    /* move buffer immediately after number we want to merge to */
+    target_number = (buffer->number < target_buffer->number) ?
+        target_buffer->number : target_buffer->number + 1;
+    if (buffer->number != target_number)
+        gui_buffer_move_to_number (buffer, target_number);
+    
+    /* change number */
+    buffer->number--;
+    
+    /* mix lines */
+    gui_line_mix_buffers (buffer);
+    
+    /* set buffer as active in merged buffers group */
+    gui_buffer_set_active_buffer (buffer);
+    
+    /* compute "number - 1" for next buffers */
+    for (ptr_buffer = buffer->next_buffer; ptr_buffer;
+         ptr_buffer = ptr_buffer->next_buffer)
+    {
+        ptr_buffer->number--;
+    }
+    
+    gui_window_ask_refresh (1);
+    
+    hook_signal_send ("buffer_merged",
+                      WEECHAT_HOOK_SIGNAL_POINTER, buffer);
+}
+
+/*
+ * gui_buffer_unmerge: unmerge a buffer from group of merged buffers
+ *                     if number >= 1, then buffer is moved to this number,
+ *                     otherwise it is moved to buffer->number + 1
+ */
+
+void
+gui_buffer_unmerge (struct t_gui_buffer *buffer, int number)
+{
+    int num_merged;
+    struct t_gui_buffer *ptr_buffer;
+    
+    /* if only one buffer then return */
+    if (gui_buffers == last_gui_buffer)
+        return;
+    
+    num_merged = gui_buffer_count_merged_buffers (buffer->number);
+    
+    /* can't unmerge if buffer is not merged to at least one buffer */
+    if (num_merged < 2)
+        return;
+    
+    /* by default, we move buffer to buffer->number + 1 */
+    if ((number < 1)  || (number == buffer->number))
+    {
+        number = buffer->number + 1;
+    }
+    else
+    {
+        if (number > last_gui_buffer->number + 1)
+            number = last_gui_buffer->number + 1;
+    }
+    
+    if (num_merged == 2)
+    {
+        /* only one buffer will remain, so it will not be merged any more */
+        gui_line_mixed_free_all (buffer);
+        gui_lines_free (buffer->mixed_lines);
+        for (ptr_buffer = gui_buffers; ptr_buffer;
+             ptr_buffer = ptr_buffer->next_buffer)
+        {
+            if (ptr_buffer->number == buffer->number)
+            {
+                ptr_buffer->active = 1;
+                ptr_buffer->mixed_lines = NULL;
+                ptr_buffer->lines = ptr_buffer->own_lines;
+            }
+        }
+    }
+    else
+    {
+        /* remove this buffer from mixed_lines, but keep other buffers merged */
+        ptr_buffer = gui_buffer_get_next_active_buffer (buffer);
+        if (ptr_buffer)
+            gui_buffer_set_active_buffer (ptr_buffer);
+        gui_line_mixed_free_buffer (buffer);
+        buffer->mixed_lines = NULL;
+        buffer->lines = buffer->own_lines;
+    }
+    
+    /* remove buffer from list */
+    if (buffer->prev_buffer)
+        (buffer->prev_buffer)->next_buffer = buffer->next_buffer;
+    if (buffer->next_buffer)
+        (buffer->next_buffer)->prev_buffer = buffer->prev_buffer;
+    if (gui_buffers == buffer)
+        gui_buffers = buffer->next_buffer;
+    if (last_gui_buffer == buffer)
+        last_gui_buffer = buffer->prev_buffer;
+    
+    /* move buffer */
+    for (ptr_buffer = gui_buffers; ptr_buffer;
+         ptr_buffer = ptr_buffer->next_buffer)
+    {
+        if (ptr_buffer->number >= number)
+            break;
+    }
+    if (ptr_buffer)
+    {
+        /* insert buffer into the list (before buffer found) */
+        buffer->prev_buffer = ptr_buffer->prev_buffer;
+        buffer->next_buffer = ptr_buffer;
+        if (ptr_buffer->prev_buffer)
+            (ptr_buffer->prev_buffer)->next_buffer = buffer;
+        else
+            gui_buffers = buffer;
+        ptr_buffer->prev_buffer = buffer;
+    }
+    else
+    {
+        /* add buffer to the end */
+        buffer->prev_buffer = last_gui_buffer;
+        buffer->next_buffer = NULL;
+        last_gui_buffer->next_buffer = buffer;
+        last_gui_buffer = buffer;
+    }
+    buffer->active = 1;
+    buffer->number = number;
+    for (ptr_buffer = buffer->next_buffer; ptr_buffer;
+         ptr_buffer = ptr_buffer->next_buffer)
+    {
+        ptr_buffer->number++;
+    }
+    
+    gui_window_ask_refresh (1);
+    
+    hook_signal_send ("buffer_unmerged",
+                      WEECHAT_HOOK_SIGNAL_POINTER, buffer);
+}
+
+/*
  * gui_buffer_visited_search: search a visited buffer in list of visited buffers
  */
 
@@ -1867,11 +2176,11 @@ gui_buffer_add_to_infolist (struct t_infolist *infolist,
         return 0;
     if (!infolist_new_var_integer (ptr_item, "print_hooks_enabled", buffer->print_hooks_enabled))
         return 0;
-    if (!infolist_new_var_integer (ptr_item, "first_line_not_read", buffer->first_line_not_read))
+    if (!infolist_new_var_integer (ptr_item, "first_line_not_read", buffer->lines->first_line_not_read))
         return 0;
-    if (!infolist_new_var_integer (ptr_item, "lines_hidden", buffer->lines_hidden))
+    if (!infolist_new_var_integer (ptr_item, "lines_hidden", buffer->lines->lines_hidden))
         return 0;
-    if (!infolist_new_var_integer (ptr_item, "prefix_max_length", buffer->prefix_max_length))
+    if (!infolist_new_var_integer (ptr_item, "prefix_max_length", buffer->lines->prefix_max_length))
         return 0;
     if (!infolist_new_var_integer (ptr_item, "time_for_each_line", buffer->time_for_each_line))
         return 0;
@@ -1939,78 +2248,6 @@ gui_buffer_add_to_infolist (struct t_infolist *infolist,
 }
 
 /*
- * gui_buffer_line_add_to_infolist: add a buffer line in an infolist
- *                                  return 1 if ok, 0 if error
- */
-
-int
-gui_buffer_line_add_to_infolist (struct t_infolist *infolist,
-                                 struct t_gui_buffer *buffer,
-                                 struct t_gui_line *line)
-{
-    struct t_infolist_item *ptr_item;
-    int i, length;
-    char option_name[64], *tags;
-    
-    if (!infolist || !line)
-        return 0;
-    
-    ptr_item = infolist_new_item (infolist);
-    if (!ptr_item)
-        return 0;
-    
-    if (!infolist_new_var_time (ptr_item, "date", line->date))
-        return 0;
-    if (!infolist_new_var_time (ptr_item, "date_printed", line->date))
-        return 0;
-    if (!infolist_new_var_string (ptr_item, "str_time", line->str_time))
-        return 0;
-    
-    /* write tags */
-    if (!infolist_new_var_integer (ptr_item, "tags_count", line->tags_count))
-        return 0;
-    length = 0;
-    for (i = 0; i < line->tags_count; i++)
-    {
-        snprintf (option_name, sizeof (option_name), "tag_%05d", i + 1);
-        if (!infolist_new_var_string (ptr_item, option_name,
-                                      line->tags_array[i]))
-            return 0;
-        length += strlen (line->tags_array[i]) + 1;
-    }
-    tags = malloc (length + 1);
-    if (!tags)
-        return 0;
-    tags[0] = '\0';
-    for (i = 0; i < line->tags_count; i++)
-    {
-        strcat (tags, line->tags_array[i]);
-        if (i < line->tags_count - 1)
-            strcat (tags, ",");
-    }
-    if (!infolist_new_var_string (ptr_item, "tags", tags))
-    {
-        free (tags);
-        return 0;
-    }
-    free (tags);
-    
-    if (!infolist_new_var_integer (ptr_item, "displayed", line->displayed))
-        return 0;
-    if (!infolist_new_var_integer (ptr_item, "highlight", line->highlight))
-        return 0;
-    if (!infolist_new_var_string (ptr_item, "prefix", line->prefix))
-        return 0;
-    if (!infolist_new_var_string (ptr_item, "message", line->message))
-        return 0;
-    if (!infolist_new_var_integer (ptr_item, "last_read_line",
-                                   (buffer->last_read_line == line) ? 1 : 0))
-        return 0;
-    
-    return 1;
-}
-
-/*
  * gui_buffer_dump_hexa: dump content of buffer as hexa data in log file
  */
 
@@ -2025,11 +2262,12 @@ gui_buffer_dump_hexa (struct t_gui_buffer *buffer)
     
     log_printf ("[buffer dump hexa (addr:0x%lx)]", buffer);
     num_line = 1;
-    for (ptr_line = buffer->lines; ptr_line; ptr_line = ptr_line->next_line)
+    for (ptr_line = buffer->lines->first_line; ptr_line;
+         ptr_line = ptr_line->next_line)
     {
         /* display line without colors */
-        message_without_colors = (ptr_line->message) ?
-            gui_color_decode (ptr_line->message, NULL) : NULL;
+        message_without_colors = (ptr_line->data->message) ?
+            gui_color_decode (ptr_line->data->message, NULL) : NULL;
         log_printf ("");
         log_printf ("  line %d: %s",
                     num_line,
@@ -2037,13 +2275,13 @@ gui_buffer_dump_hexa (struct t_gui_buffer *buffer)
                     message_without_colors : "(null)");
         if (message_without_colors)
             free (message_without_colors);
-        tags = string_build_with_exploded ((const char **)ptr_line->tags_array, ",");
+        tags = string_build_with_exploded ((const char **)ptr_line->data->tags_array, ",");
         log_printf ("  tags: %s", (tags) ? tags : "(none)");
         if (tags)
             free (tags);
         
         /* display raw message for line */
-        if (ptr_line->message)
+        if (ptr_line->data->message)
         {
             log_printf ("");
             log_printf ("  raw data for line %d (with color codes):",
@@ -2051,15 +2289,15 @@ gui_buffer_dump_hexa (struct t_gui_buffer *buffer)
             msg_pos = 0;
             hexa_pos = 0;
             ascii_pos = 0;
-            while (ptr_line->message[msg_pos])
+            while (ptr_line->data->message[msg_pos])
             {
                 snprintf (hexa + hexa_pos, 4, "%02X ",
-                          (unsigned char)(ptr_line->message[msg_pos]));
+                          (unsigned char)(ptr_line->data->message[msg_pos]));
                 hexa_pos += 3;
                 snprintf (ascii + ascii_pos, 3, "%c ",
-                          ((((unsigned char)ptr_line->message[msg_pos]) < 32)
-                           || (((unsigned char)ptr_line->message[msg_pos]) > 127)) ?
-                          '.' : (unsigned char)(ptr_line->message[msg_pos]));
+                          ((((unsigned char)ptr_line->data->message[msg_pos]) < 32)
+                           || (((unsigned char)ptr_line->data->message[msg_pos]) > 127)) ?
+                          '.' : (unsigned char)(ptr_line->data->message[msg_pos]));
                 ascii_pos += 2;
                 if (ascii_pos == 32)
                 {
@@ -2106,17 +2344,16 @@ gui_buffer_print_log ()
         log_printf ("  type . . . . . . . . . : %d",    ptr_buffer->type);
         log_printf ("  notify . . . . . . . . : %d",    ptr_buffer->notify);
         log_printf ("  num_displayed. . . . . : %d",    ptr_buffer->num_displayed);
+        log_printf ("  active . . . . . . . . : %d",    ptr_buffer->active);
         log_printf ("  print_hooks_enabled. . : %d",    ptr_buffer->print_hooks_enabled);
         log_printf ("  close_callback . . . . : 0x%lx", ptr_buffer->close_callback);
         log_printf ("  close_callback_data. . : 0x%lx", ptr_buffer->close_callback_data);
         log_printf ("  title. . . . . . . . . : '%s'",  ptr_buffer->title);
+        log_printf ("  own_lines. . . . . . . : 0x%lx", ptr_buffer->own_lines);
+        gui_lines_print_log (ptr_buffer->own_lines);
+        log_printf ("  mixed_lines. . . . . . : 0x%lx", ptr_buffer->mixed_lines);
+        gui_lines_print_log (ptr_buffer->mixed_lines);
         log_printf ("  lines. . . . . . . . . : 0x%lx", ptr_buffer->lines);
-        log_printf ("  last_line. . . . . . . : 0x%lx", ptr_buffer->last_line);
-        log_printf ("  last_read_line . . . . : 0x%lx", ptr_buffer->last_read_line);
-        log_printf ("  first_line_not_read. . : %d",    ptr_buffer->first_line_not_read);
-        log_printf ("  lines_count. . . . . . : %d",    ptr_buffer->lines_count);
-        log_printf ("  lines_hidden . . . . . : %d",    ptr_buffer->lines_hidden);
-        log_printf ("  prefix_max_length. . . : %d",    ptr_buffer->prefix_max_length);
         log_printf ("  time_for_each_line . . : %d",    ptr_buffer->time_for_each_line);
         log_printf ("  chat_refresh_needed. . : %d",    ptr_buffer->chat_refresh_needed);
         log_printf ("  nicklist . . . . . . . : %d",    ptr_buffer->nicklist);
@@ -2150,6 +2387,8 @@ gui_buffer_print_log ()
         log_printf ("  highlight_tags_array . : 0x%lx", ptr_buffer->highlight_tags_array);
         log_printf ("  keys . . . . . . . . . : 0x%lx", ptr_buffer->keys);
         log_printf ("  last_key . . . . . . . : 0x%lx", ptr_buffer->last_key);
+        log_printf ("  local_variables. . . . : 0x%lx", ptr_buffer->local_variables);
+        log_printf ("  last_local_var . . . . : 0x%lx", ptr_buffer->last_local_var);
         log_printf ("  prev_buffer. . . . . . : 0x%lx", ptr_buffer->prev_buffer);
         log_printf ("  next_buffer. . . . . . : 0x%lx", ptr_buffer->next_buffer);
         
@@ -2184,31 +2423,31 @@ gui_buffer_print_log ()
         log_printf ("");
         log_printf ("  => last 100 lines:");
         num = 0;
-        ptr_line = ptr_buffer->last_line;
+        ptr_line = ptr_buffer->lines->last_line;
         while (ptr_line && (num < 100))
         {
             num++;
             ptr_line = ptr_line->prev_line;
         }
         if (!ptr_line)
-            ptr_line = ptr_buffer->lines;
+            ptr_line = ptr_buffer->lines->first_line;
         else
             ptr_line = ptr_line->next_line;
         
         while (ptr_line)
         {
             num--;
-            tags = string_build_with_exploded ((const char **)ptr_line->tags_array, ",");
+            tags = string_build_with_exploded ((const char **)ptr_line->data->tags_array, ",");
             log_printf ("       line N-%05d: y:%d, str_time:'%s', tags:'%s', "
                         "displayed:%d, highlight:%d, refresh_needed:%d, prefix:'%s'",
-                        num, ptr_line->y, ptr_line->str_time,
+                        num, ptr_line->data->y, ptr_line->data->str_time,
                         (tags) ? tags  : "",
-                        (int)(ptr_line->displayed),
-                        (int) (ptr_line->highlight),
-                        (int)(ptr_line->refresh_needed),
-                        ptr_line->prefix);
+                        (int)(ptr_line->data->displayed),
+                        (int)(ptr_line->data->highlight),
+                        (int)(ptr_line->data->refresh_needed),
+                        ptr_line->data->prefix);
             log_printf ("                     data: '%s'",
-                        ptr_line->message);
+                        ptr_line->data->message);
             if (tags)
                 free (tags);
             
diff --git a/src/gui/gui-buffer.h b/src/gui/gui-buffer.h
index c46033d6f..58c251d6c 100644
--- a/src/gui/gui-buffer.h
+++ b/src/gui/gui-buffer.h
@@ -49,24 +49,6 @@ enum t_gui_buffer_notify
 
 /* buffer structures */
 
-struct t_gui_line
-{
-    int y;                             /* line position (for free buffer)   */
-    time_t date;                       /* date/time of line (may be past)   */
-    time_t date_printed;               /* date/time when weechat print it   */
-    char *str_time;                    /* time string (for display)         */
-    int tags_count;                    /* number of tags for line           */
-    char **tags_array;                 /* tags for line                     */
-    char displayed;                    /* 1 if line is displayed            */
-    char highlight;                    /* 1 if line has highlight           */
-    char refresh_needed;               /* 1 if refresh asked (free buffer)  */
-    char *prefix;                      /* prefix for line (may be NULL)     */
-    int prefix_length;                 /* prefix length (on screen)         */
-    char *message;                     /* line content (after prefix)       */
-    struct t_gui_line *prev_line;      /* link to previous line             */
-    struct t_gui_line *next_line;      /* link to next line                 */
-};
-
 struct t_gui_buffer_local_var
 {
     char *name;                        /* variable name                     */
@@ -83,6 +65,10 @@ struct t_gui_buffer
        to store plugin name, then restore plugin pointer when plugin is
        loaded */
     char *plugin_name_for_upgrade;     /* plugin name when upgrading        */
+    /* when upgrading, we use this pointer to remember that this buffer
+       must merge with another buffer (it's done when all buffers are
+       restored) */
+    struct t_gui_buffer *merge_for_upgrade;
     
     int number;                        /* buffer number (for jump/switch)   */
     int layout_number;                 /* the number of buffer saved in     */
@@ -95,6 +81,9 @@ struct t_gui_buffer
                                        /* 2 = highlight + msg               */
                                        /* 3 = highlight + msg + join/part   */
     int num_displayed;                 /* number of windows displaying buf. */
+    int active;                        /* it is 0 only if buffers are       */
+                                       /* merged and that this one is not   */
+                                       /* selected buffer                   */
     int print_hooks_enabled;           /* 1 if print hooks are enabled      */
     
     /* close callback */
@@ -106,13 +95,10 @@ struct t_gui_buffer
     char *title;                       /* buffer title                      */
     
     /* chat content */
-    struct t_gui_line *lines;          /* lines of chat window              */
-    struct t_gui_line *last_line;      /* last line of chat window          */
-    struct t_gui_line *last_read_line; /* last read line before jump        */
-    int first_line_not_read;           /* if 1, marker is before first line */ 
-    int lines_count;                   /* number of lines in the buffer     */
-    int lines_hidden;                  /* 1 if at least one line is hidden  */
-    int prefix_max_length;             /* length for prefix align           */
+    struct t_gui_lines *own_lines;     /* lines (for this buffer only)      */
+    struct t_gui_lines *mixed_lines;   /* mixed lines (if buffers merged)   */
+    struct t_gui_lines *lines;         /* pointer to "own_lines" or         */
+                                       /* "mixed_lines"                     */
     int time_for_each_line;            /* time is displayed for each line?  */
     int chat_refresh_needed;           /* refresh for chat is needed ?      */
                                        /* (1=refresh, 2=erase+refresh)      */
@@ -230,6 +216,8 @@ extern void gui_buffer_set (struct t_gui_buffer *buffer, const char *property,
                             const char *value);
 extern void gui_buffer_set_pointer (struct t_gui_buffer *buffer,
                                     const char *property, void *pointer);
+extern void gui_buffer_add_value_num_displayed (struct t_gui_buffer *buffer,
+                                                int value);
 extern struct t_gui_buffer *gui_buffer_search_main ();
 extern struct t_gui_buffer *gui_buffer_search_by_name (const char *plugin,
                                                        const char *name);
@@ -242,7 +230,12 @@ extern void gui_buffer_clear_all ();
 extern void gui_buffer_close (struct t_gui_buffer *buffer);
 extern void gui_buffer_switch_by_number (struct t_gui_window *window,
                                          int number);
+extern void gui_buffer_set_active_buffer (struct t_gui_buffer *buffer);
+extern struct t_gui_buffer *gui_buffer_get_next_active_buffer (struct t_gui_buffer *buffer);
 extern void gui_buffer_move_to_number (struct t_gui_buffer *buffer, int number);
+extern void gui_buffer_merge (struct t_gui_buffer *buffer,
+                              struct t_gui_buffer *target_buffer);
+extern void gui_buffer_unmerge (struct t_gui_buffer *buffer, int number);
 extern struct t_gui_buffer_visited *gui_buffer_visited_search_by_number (int number);
 extern void gui_buffer_visited_remove (struct t_gui_buffer_visited *buffer_visited);
 extern void gui_buffer_visited_remove_by_buffer (struct t_gui_buffer *buffer);
@@ -251,9 +244,6 @@ extern int gui_buffer_visited_get_index_previous ();
 extern int gui_buffer_visited_get_index_next ();
 extern int gui_buffer_add_to_infolist (struct t_infolist *infolist,
                                        struct t_gui_buffer *buffer);
-extern int gui_buffer_line_add_to_infolist (struct t_infolist *infolist,
-                                            struct t_gui_buffer *buffer,
-                                            struct t_gui_line *line);
 extern void gui_buffer_dump_hexa (struct t_gui_buffer *buffer);
 extern void gui_buffer_print_log ();
 
diff --git a/src/gui/gui-chat.c b/src/gui/gui-chat.c
index ab881fcb0..80f11e611 100644
--- a/src/gui/gui-chat.c
+++ b/src/gui/gui-chat.c
@@ -41,7 +41,7 @@
 #include "gui-buffer.h"
 #include "gui-color.h"
 #include "gui-filter.h"
-#include "gui-hotlist.h"
+#include "gui-line.h"
 #include "gui-main.h"
 #include "gui-window.h"
 
@@ -359,420 +359,20 @@ gui_chat_change_time_format ()
     for (ptr_buffer = gui_buffers; ptr_buffer;
          ptr_buffer = ptr_buffer->next_buffer)
     {
-        for (ptr_line = ptr_buffer->lines; ptr_line;
+        for (ptr_line = ptr_buffer->lines->first_line; ptr_line;
              ptr_line = ptr_line->next_line)
         {
-            if (ptr_line->date != 0)
+            if (ptr_line->data->date != 0)
             {
-                if (ptr_line->str_time)
-                    free (ptr_line->str_time);
-                ptr_line->str_time = gui_chat_get_time_string (ptr_line->date);
+                if (ptr_line->data->str_time)
+                    free (ptr_line->data->str_time);
+                ptr_line->data->str_time = gui_chat_get_time_string (ptr_line->data->date);
             }
         }
     }
 }
 
 /*
- * gui_chat_get_line_align: get alignment for a line
- */
-
-int
-gui_chat_get_line_align (struct t_gui_buffer *buffer, struct t_gui_line *line,
-                         int with_suffix)
-{
-    int time_length, length_suffix;
-    
-    time_length = (buffer->time_for_each_line) ? gui_chat_time_length : 0;
-    
-    if (CONFIG_INTEGER(config_look_prefix_align) == CONFIG_LOOK_PREFIX_ALIGN_NONE)
-        return time_length + 1 + line->prefix_length + 2;
-    
-    length_suffix = 0;
-    if (with_suffix)
-    {
-        if (CONFIG_STRING(config_look_prefix_suffix)
-            && CONFIG_STRING(config_look_prefix_suffix)[0])
-            length_suffix = gui_chat_strlen_screen (CONFIG_STRING(config_look_prefix_suffix)) + 1;
-    }
-    return time_length + ((buffer->prefix_max_length > 0) ? 1 : 0) +
-        + (((CONFIG_INTEGER(config_look_prefix_align_max) > 0)
-            && (buffer->prefix_max_length > CONFIG_INTEGER(config_look_prefix_align_max))) ?
-           CONFIG_INTEGER(config_look_prefix_align_max) : buffer->prefix_max_length)
-        + length_suffix + 1;
-}
-
-/*
- * gui_chat_line_displayed: return 1 if line is displayed (no filter on line,
- *                          or filters disabled), 0 if line is hidden
- */
-
-int
-gui_chat_line_displayed (struct t_gui_line *line)
-{
-    /* line is hidden if filters are enabled and flag "displayed" is not set */
-    if (gui_filters_enabled && !line->displayed)
-        return 0;
-    
-    /* in all other cases, line is displayed */
-    return 1;
-}
-
-/*
- * gui_chat_get_first_line_displayed: get first line displayed of a buffer
- */
-
-struct t_gui_line *
-gui_chat_get_first_line_displayed (struct t_gui_buffer *buffer)
-{
-    struct t_gui_line *ptr_line;
-    
-    ptr_line = buffer->lines;
-    while (ptr_line && !gui_chat_line_displayed (ptr_line))
-    {
-        ptr_line = ptr_line->next_line;
-    }
-    
-    return ptr_line;
-}
-
-/*
- * gui_chat_get_last_line_displayed: get last line displayed of a buffer
- */
-
-struct t_gui_line *
-gui_chat_get_last_line_displayed (struct t_gui_buffer *buffer)
-{
-    struct t_gui_line *ptr_line;
-    
-    ptr_line = buffer->last_line;
-    while (ptr_line && !gui_chat_line_displayed (ptr_line))
-    {
-        ptr_line = ptr_line->prev_line;
-    }
-    
-    return ptr_line;
-}
-
-/*
- * gui_chat_get_prev_line_displayed: get previous line displayed
- */
-
-struct t_gui_line *
-gui_chat_get_prev_line_displayed (struct t_gui_line *line)
-{
-    if (line)
-    {
-        line = line->prev_line;
-        while (line && !gui_chat_line_displayed (line))
-        {
-            line = line->prev_line;
-        }
-    }
-    return line;
-}
-
-/*
- * gui_chat_get_next_line_displayed: get next line displayed
- */
-
-struct t_gui_line *
-gui_chat_get_next_line_displayed (struct t_gui_line *line)
-{
-    if (line)
-    {
-        line = line->next_line;
-        while (line && !gui_chat_line_displayed (line))
-        {
-            line = line->next_line;
-        }
-    }
-    return line;
-}
-
-/*
- * gui_chat_line_search: search for text in a line
- */
-
-int
-gui_chat_line_search (struct t_gui_line *line, const char *text,
-                      int case_sensitive)
-{
-    char *prefix, *message;
-    int rc;
-    
-    if (!line || !line->message || !text || !text[0])
-        return 0;
-    
-    rc = 0;
-    
-    if (line->prefix)
-    {
-        prefix = gui_color_decode (line->prefix, NULL);
-        if (prefix)
-        {
-            if ((case_sensitive && (strstr (prefix, text)))
-                || (!case_sensitive && (string_strcasestr (prefix, text))))
-                rc = 1;
-            free (prefix);
-        }
-    }
-    
-    if (!rc)
-    {
-        message = gui_color_decode (line->message, NULL);
-        if (message)
-        {
-            if ((case_sensitive && (strstr (message, text)))
-                || (!case_sensitive && (string_strcasestr (message, text))))
-                rc = 1;
-            free (message);
-        }
-    }
-    
-    return rc;
-}
-
-/*
- * gui_chat_line_match_regex: return 1 if message matches regex
- *                            0 if it doesn't match
- */
-
-int
-gui_chat_line_match_regex (struct t_gui_line *line, regex_t *regex_prefix,
-                           regex_t *regex_message)
-{
-    char *prefix, *message;
-    int match_prefix, match_message;
-    
-    if (!line || (!regex_prefix && !regex_message))
-        return 0;
-    
-    prefix = NULL;
-    message = NULL;
-    
-    match_prefix = 1;
-    match_message = 1;
-
-    if (line->prefix)
-    {
-        prefix = gui_color_decode (line->prefix, NULL);
-        if (!prefix
-            || (regex_prefix && (regexec (regex_prefix, prefix, 0, NULL, 0) != 0)))
-            match_prefix = 0;
-    }
-    else
-    {
-        if (regex_prefix)
-            match_prefix = 0;
-    }
-
-    if (line->message)
-    {
-        message = gui_color_decode (line->message, NULL);
-        if (!message
-            || (regex_message && (regexec (regex_message, message, 0, NULL, 0) != 0)))
-            match_message = 0;
-    }
-    else
-    {
-        if (regex_message)
-            match_message = 0;
-    }
-    
-    if (prefix)
-        free (prefix);
-    if (message)
-        free (message);
-    
-    return (match_prefix && match_message);
-}
-
-/*
- * gui_chat_line_match_tags: return 1 if line matches tags
- *                           0 if it doesn't match any tag in array
- */
-
-int
-gui_chat_line_match_tags (struct t_gui_line *line, int tags_count,
-                          char **tags_array)
-{
-    int i, j;
-    
-    if (!line)
-        return 0;
-    
-    if (line->tags_count == 0)
-        return 0;
-    
-    for (i = 0; i < tags_count; i++)
-    {
-        for (j = 0; j < line->tags_count; j++)
-        {
-            /* check tag */
-            if (string_match (line->tags_array[j],
-                              tags_array[i],
-                              0))
-                return 1;
-        }
-    }
-    
-    return 0;
-}
-
-/*
- * gui_chat_line_has_highlight: return 1 if given message contains highlight (with
- *                              a string in global highlight or buffer highlight)
- */
-
-int
-gui_chat_line_has_highlight (struct t_gui_buffer *buffer,
-                             struct t_gui_line *line)
-{
-    int rc, i;
-    char *msg_no_color;
-    
-    /* highlights are disabled on this buffer? (special value "-" means that
-       buffer does not want any highlight) */
-    if (buffer->highlight_words && (strcmp (buffer->highlight_words, "-") == 0))
-        return 0;
-    
-    /* check if highlight is disabled for line */
-    for (i = 0; i < line->tags_count; i++)
-    {
-        if (strcmp (line->tags_array[i], GUI_CHAT_TAG_NO_HIGHLIGHT) == 0)
-            return 0;
-    }
-    
-    /* check that line matches highlight tags, if any (if no tag is specified,
-       then any tag is allowed) */
-    if (buffer->highlight_tags_count > 0)
-    {
-        if (!gui_chat_line_match_tags (line,
-                                       buffer->highlight_tags_count,
-                                       buffer->highlight_tags_array))
-            return 0;
-    }
-    
-    /* remove color codes from line message */
-    msg_no_color = gui_color_decode (line->message, NULL);
-    if (!msg_no_color)
-        return 0;
-    
-    /* there is highlight on line if one of global highlight words matches line
-       or one of buffer highlight words matches line */
-    rc = (string_has_highlight (msg_no_color,
-                                CONFIG_STRING(config_look_highlight)) ||
-          string_has_highlight (msg_no_color,
-                                buffer->highlight_words));
-    
-    free (msg_no_color);
-    
-    return rc;
-}
-
-/*
- * gui_chat_line_free: delete a formatted line from a buffer
- */
-
-void
-gui_chat_line_free (struct t_gui_buffer *buffer, struct t_gui_line *line)
-{
-    int update_prefix_max_length;
-    struct t_gui_line *ptr_line;
-    struct t_gui_window *ptr_win;
-    
-    update_prefix_max_length = (line->prefix_length == buffer->prefix_max_length);
-    
-    /* reset scroll for any window starting with this line */
-    for (ptr_win = gui_windows; ptr_win; ptr_win = ptr_win->next_window)
-    {
-        if (ptr_win->start_line == line)
-        {
-            ptr_win->start_line = ptr_win->start_line->next_line;
-            ptr_win->start_line_pos = 0;
-            gui_buffer_ask_chat_refresh (buffer, 2);
-        }
-    }
-    
-    /* move read marker if it was on line we are removing */
-    if (buffer->last_read_line == line)
-    {
-        buffer->last_read_line = buffer->last_read_line->prev_line;
-        buffer->first_line_not_read = (buffer->last_read_line) ? 0 : 1;
-        gui_buffer_ask_chat_refresh (buffer, 1);
-    }
-    
-    /* free data */
-    if (line->str_time)
-        free (line->str_time);
-    if (line->tags_array)
-        string_free_exploded (line->tags_array);
-    if (line->prefix)
-        free (line->prefix);
-    if (line->message)
-        free (line->message);
-    
-    /* remove line from lines list */
-    if (line->prev_line)
-        (line->prev_line)->next_line = line->next_line;
-    if (line->next_line)
-        (line->next_line)->prev_line = line->prev_line;
-    if (buffer->lines == line)
-        buffer->lines = line->next_line;
-    if (buffer->last_line == line)
-        buffer->last_line = line->prev_line;
-    
-    free (line);
-    
-    buffer->lines_count--;
-
-    if (update_prefix_max_length)
-    {
-        buffer->prefix_max_length = 0;
-        for (ptr_line = buffer->lines; ptr_line;
-             ptr_line = ptr_line->next_line)
-        {
-            if (ptr_line->prefix_length > buffer->prefix_max_length)
-                buffer->prefix_max_length = ptr_line->prefix_length;
-        }
-    }
-}
-
-/*
- * gui_chat_line_free_all: delete all formatted lines from a buffer
- */
-
-void
-gui_chat_line_free_all (struct t_gui_buffer *buffer)
-{
-    while (buffer->lines)
-    {
-        gui_chat_line_free (buffer, buffer->lines);
-    }
-}
-
-/*
- * gui_chat_line_get_notify_level: get notify level for a line
- */
-
-int
-gui_chat_line_get_notify_level (struct t_gui_line *line)
-{
-    int i;
-    
-    for (i = 0; i < line->tags_count; i++)
-    {
-        if (string_strcasecmp (line->tags_array[i], "notify_highlight") == 0)
-            return GUI_HOTLIST_HIGHLIGHT;
-        if (string_strcasecmp (line->tags_array[i], "notify_private") == 0)
-            return GUI_HOTLIST_PRIVATE;
-        if (string_strcasecmp (line->tags_array[i], "notify_message") == 0)
-            return GUI_HOTLIST_MESSAGE;
-    }
-    return GUI_HOTLIST_LOW;
-}
-
-/*
  * gui_chat_build_string_prefix_message: build a string with prefix and message
  */
 
@@ -783,22 +383,22 @@ gui_chat_build_string_prefix_message (struct t_gui_line *line)
     int length;
     
     length = 0;
-    if (line->prefix)
-        length += strlen (line->prefix);
+    if (line->data->prefix)
+        length += strlen (line->data->prefix);
     length++;
-    if (line->message)
-        length += strlen (line->message);
+    if (line->data->message)
+        length += strlen (line->data->message);
     length++;
     
     string = malloc (length);
     if (string)
     {
         string[0] = '\0';
-        if (line->prefix)
-            strcat (string, line->prefix);
+        if (line->data->prefix)
+            strcat (string, line->data->prefix);
         strcat (string, "\t");
-        if (line->message)
-            strcat (string, line->message);
+        if (line->data->message)
+            strcat (string, line->data->message);
     }
 
     if (string)
@@ -815,219 +415,6 @@ gui_chat_build_string_prefix_message (struct t_gui_line *line)
 }
 
 /*
- * gui_chat_line_add: add a new line for a buffer
- */
-
-struct t_gui_line *
-gui_chat_line_add (struct t_gui_buffer *buffer, time_t date,
-                   time_t date_printed, const char *tags,
-                   const char *prefix, const char *message)
-{
-    struct t_gui_line *new_line;
-    struct t_gui_window *ptr_win;
-    char *message_for_signal;
-    int notify_level;
-    
-    new_line = malloc (sizeof (*new_line));
-    if (!new_line)
-    {
-        log_printf (_("Not enough memory for new line"));
-        return NULL;
-    }
-    
-    /* fill data in new line */
-    new_line->y = 0;
-    new_line->date = date;
-    new_line->date_printed = date_printed;
-    new_line->str_time = (date == 0) ?
-        NULL : gui_chat_get_time_string (date);
-    if (tags)
-    {
-        new_line->tags_array = string_explode (tags, ",", 0, 0,
-                                               &new_line->tags_count);
-    }
-    else
-    {
-        new_line->tags_count = 0;
-        new_line->tags_array = NULL;
-    }
-    new_line->refresh_needed = 0;
-    new_line->prefix = (prefix) ?
-        strdup (prefix) : ((date != 0) ? strdup ("") : NULL);
-    new_line->prefix_length = (prefix) ?
-        gui_chat_strlen_screen (prefix) : 0;
-    new_line->message = (message) ? strdup (message) : strdup ("");
-    new_line->highlight = gui_chat_line_has_highlight (buffer, new_line);
-    
-    /* add line to lines list */
-    if (!buffer->lines)
-        buffer->lines = new_line;
-    else
-        buffer->last_line->next_line = new_line;
-    new_line->prev_line = buffer->last_line;
-    new_line->next_line = NULL;
-    buffer->last_line = new_line;
-    buffer->lines_count++;
-    
-    /* check if line is filtered or not */
-    new_line->displayed = gui_filter_check_line (buffer, new_line);
-    if (new_line->displayed)
-    {
-        if (new_line->prefix_length > buffer->prefix_max_length)
-            buffer->prefix_max_length = new_line->prefix_length;
-        if (new_line->highlight)
-        {
-            gui_hotlist_add (buffer, GUI_HOTLIST_HIGHLIGHT, NULL, 1);
-            if (!weechat_upgrading)
-            {
-                message_for_signal = gui_chat_build_string_prefix_message (new_line);
-                if (message_for_signal)
-                {
-                    hook_signal_send ("weechat_highlight",
-                                      WEECHAT_HOOK_SIGNAL_STRING,
-                                      message_for_signal);
-                    free (message_for_signal);
-                }
-            }
-        }
-        else
-        {
-            notify_level = gui_chat_line_get_notify_level (new_line);
-            if (!weechat_upgrading && (notify_level == GUI_HOTLIST_PRIVATE))
-            {
-                message_for_signal = gui_chat_build_string_prefix_message (new_line);
-                if (message_for_signal)
-                {
-                    hook_signal_send ("weechat_pv",
-                                      WEECHAT_HOOK_SIGNAL_STRING,
-                                      message_for_signal);
-                    free (message_for_signal);
-                }
-            }
-            gui_hotlist_add (buffer, notify_level, NULL, 1);
-        }
-    }
-    else
-    {
-        if (!buffer->lines_hidden)
-        {
-            buffer->lines_hidden = 1;
-            hook_signal_send ("buffer_lines_hidden",
-                              WEECHAT_HOOK_SIGNAL_POINTER, buffer);
-        }
-    }
-    
-    /* remove one line if necessary */
-    if ((CONFIG_INTEGER(config_history_max_lines) > 0)
-        && (buffer->lines_count > CONFIG_INTEGER(config_history_max_lines)))
-    {
-        gui_chat_line_free (buffer, buffer->lines);
-        for (ptr_win = gui_windows; ptr_win; ptr_win = ptr_win->next_window)
-        {
-            if ((ptr_win->buffer == buffer)
-                && (buffer->lines_count < ptr_win->win_chat_height))
-            {
-                gui_buffer_ask_chat_refresh (buffer, 2);
-                break;
-            }
-        }
-    }
-    
-    return new_line;
-}
-
-/*
- * gui_chat_line_add_y: add or update a line for a buffer with free content
- */
-
-void
-gui_chat_line_add_y (struct t_gui_buffer *buffer, int y, const char *message)
-{
-    struct t_gui_line *ptr_line, *new_line;
-    
-    if (!message || !message[0])
-        return;
-    
-    /* search if line exists for "y" */
-    for (ptr_line = buffer->lines; ptr_line;
-         ptr_line = ptr_line->next_line)
-    {
-        if (ptr_line->y >= y)
-            break;
-    }
-    
-    if (!ptr_line || (ptr_line->y > y))
-    {
-        new_line = malloc (sizeof (*new_line));
-        if (!new_line)
-        {
-            log_printf (_("Not enough memory for new line"));
-            return;
-        }
-        
-        buffer->lines_count++;
-        
-        /* fill data in new line */
-        new_line->y = y;
-        new_line->date = 0;
-        new_line->date_printed = 0;
-        new_line->str_time = NULL;
-        new_line->tags_count = 0;
-        new_line->tags_array = NULL;
-        new_line->refresh_needed = 1;
-        new_line->prefix = NULL;
-        new_line->prefix_length = 0;
-        new_line->message = NULL;
-        new_line->highlight = 0;
-        
-        /* add line to lines list */
-        if (ptr_line)
-        {
-            /* add before line found */
-            new_line->prev_line = ptr_line->prev_line;
-            new_line->next_line = ptr_line;
-            if (ptr_line->prev_line)
-                (ptr_line->prev_line)->next_line = new_line;
-            else
-                buffer->lines = new_line;
-            ptr_line->prev_line = new_line;
-        }
-        else
-        {
-            /* add at end of list */
-            new_line->prev_line = buffer->last_line;
-            if (buffer->lines)
-                buffer->last_line->next_line = new_line;
-            else
-                buffer->lines = new_line;
-            buffer->last_line = new_line;
-            new_line->next_line = NULL;
-        }
-
-        ptr_line = new_line;
-    }
-    
-    /* set message for line */
-    if (ptr_line->message)
-        free (ptr_line->message);
-    ptr_line->message = strdup (message);
-    
-    /* check if line is filtered or not */
-    ptr_line->displayed = gui_filter_check_line (buffer, ptr_line);
-    if (!ptr_line->displayed)
-    {
-        if (!buffer->lines_hidden)
-        {
-            buffer->lines_hidden = 1;
-            hook_signal_send ("buffer_lines_hidden",
-                              WEECHAT_HOOK_SIGNAL_POINTER, buffer);
-        }
-    }
-    
-    ptr_line->refresh_needed = 1;
-}
-
-/*
  * gui_chat_printf_date_tags: display a message in a buffer with optional
  *                            date and tags
  *                            Info: this function works only with formatted
@@ -1082,7 +469,7 @@ gui_chat_printf_date_tags (struct t_gui_buffer *buffer, time_t date,
         date = date_printed;
     
     if (gui_init_ok)
-        ptr_line = buffer->last_line;
+        ptr_line = buffer->lines->last_line;
     
     at_least_one_message_printed = 0;
     
@@ -1153,12 +540,12 @@ gui_chat_printf_date_tags (struct t_gui_buffer *buffer, time_t date,
         
         if (gui_init_ok)
         {
-            gui_chat_line_add (buffer, (display_time) ? date : 0,
-                               (display_time) ? date_printed : 0,
-                               tags, pos_prefix, ptr_msg);
-            if (buffer->last_line && buffer->print_hooks_enabled)
+            gui_line_add (buffer, (display_time) ? date : 0,
+                          (display_time) ? date_printed : 0,
+                          tags, pos_prefix, ptr_msg);
+            if (buffer->lines->last_line && buffer->print_hooks_enabled)
             {
-                hook_print_exec (buffer, buffer->last_line);
+                hook_print_exec (buffer, buffer->lines->last_line);
             }
             at_least_one_message_printed = 1;
         }
@@ -1219,15 +606,15 @@ gui_chat_printf_y (struct t_gui_buffer *buffer, int y, const char *message, ...)
     {
         if (gui_init_ok)
         {
-            for (ptr_line = buffer->lines; ptr_line;
+            for (ptr_line = buffer->lines->first_line; ptr_line;
                  ptr_line = ptr_line->next_line)
             {
-                if (ptr_line->y >= y)
+                if (ptr_line->data->y >= y)
                     break;
             }
-            if (ptr_line && (ptr_line->y == y))
+            if (ptr_line && (ptr_line->data->y == y))
             {
-                gui_chat_line_free (buffer, ptr_line);
+                gui_line_free (buffer, ptr_line);
                 gui_buffer_ask_chat_refresh (buffer, 2);
             }
         }
@@ -1236,7 +623,7 @@ gui_chat_printf_y (struct t_gui_buffer *buffer, int y, const char *message, ...)
     {
         if (gui_init_ok)
         {
-            gui_chat_line_add_y (buffer, y, gui_chat_buffer);
+            gui_line_add_y (buffer, y, gui_chat_buffer);
             gui_buffer_ask_chat_refresh (buffer, 1);
         }
         else
diff --git a/src/gui/gui-chat.h b/src/gui/gui-chat.h
index 12ddeb1b7..791184b17 100644
--- a/src/gui/gui-chat.h
+++ b/src/gui/gui-chat.h
@@ -20,8 +20,6 @@
 #ifndef __WEECHAT_GUI_CHAT_H
 #define __WEECHAT_GUI_CHAT_H 1
 
-#include <regex.h>
-
 struct t_gui_window;
 struct t_gui_buffer;
 struct t_gui_line;
@@ -60,31 +58,9 @@ extern void gui_chat_get_word_info (struct t_gui_window *window,
                                     int *word_end_offset,
                                     int *word_length_with_spaces,
                                     int *word_length);
+extern char *gui_chat_get_time_string (time_t date);
 extern void gui_chat_change_time_format ();
-extern int gui_chat_get_line_align (struct t_gui_buffer *buffer,
-                                    struct t_gui_line *line,
-                                    int with_suffix);
-extern int gui_chat_line_displayed (struct t_gui_line *line);
-extern struct t_gui_line *gui_chat_get_first_line_displayed (struct t_gui_buffer *buffer);
-extern struct t_gui_line *gui_chat_get_last_line_displayed (struct t_gui_buffer *buffer);
-extern struct t_gui_line *gui_chat_get_prev_line_displayed (struct t_gui_line *line);
-extern struct t_gui_line *gui_chat_get_next_line_displayed (struct t_gui_line *line);
-extern int gui_chat_line_search (struct t_gui_line *line, const char *text,
-                                 int case_sensitive);
-extern int gui_chat_line_match_regex (struct t_gui_line *line,
-                                      regex_t *regex_prefix,
-                                      regex_t *regex_message);
-extern int gui_chat_line_match_tags (struct t_gui_line *line, int tags_count,
-                                     char **tags_array);
-extern void gui_chat_line_free (struct t_gui_buffer *buffer,
-                                struct t_gui_line *line);
-extern void gui_chat_line_free_all (struct t_gui_buffer *buffer);
-extern struct t_gui_line *gui_chat_line_add (struct t_gui_buffer *buffer,
-                                             time_t date,
-                                             time_t date_printed,
-                                             const char *tags,
-                                             const char *prefix,
-                                             const char *message);
+extern char *gui_chat_build_string_prefix_message (struct t_gui_line *line);
 extern void gui_chat_printf_date_tags (struct t_gui_buffer *buffer,
                                        time_t date, const char *tags,
                                        const char *message, ...);
diff --git a/src/gui/gui-color.h b/src/gui/gui-color.h
index 50cee70d0..7feae6497 100644
--- a/src/gui/gui-color.h
+++ b/src/gui/gui-color.h
@@ -58,6 +58,7 @@ enum t_gui_color_enum
     GUI_COLOR_CHAT_READ_MARKER,
     GUI_COLOR_CHAT_TEXT_FOUND,
     GUI_COLOR_CHAT_VALUE,
+    GUI_COLOR_CHAT_PREFIX_BUFFER,
     
     /* number of colors */
     GUI_COLOR_NUM_COLORS,
diff --git a/src/gui/gui-filter.c b/src/gui/gui-filter.c
index 5e823e3b0..4906f7a93 100644
--- a/src/gui/gui-filter.c
+++ b/src/gui/gui-filter.c
@@ -35,7 +35,7 @@
 #include "../plugins/plugin.h"
 #include "gui-filter.h"
 #include "gui-buffer.h"
-#include "gui-chat.h"
+#include "gui-line.h"
 
 
 struct t_gui_filter *gui_filters = NULL;           /* first filter          */
@@ -54,9 +54,9 @@ gui_filter_line_has_tag_no_filter (struct t_gui_line *line)
 {
     int i;
     
-    for (i = 0; i < line->tags_count; i++)
+    for (i = 0; i < line->data->tags_count; i++)
     {
-        if (strcmp (line->tags_array[i], GUI_FILTER_TAG_NO_FILTER) == 0)
+        if (strcmp (line->data->tags_array[i], GUI_FILTER_TAG_NO_FILTER) == 0)
             return 1;
     }
     
@@ -92,17 +92,17 @@ gui_filter_check_line (struct t_gui_buffer *buffer, struct t_gui_line *line)
                 && string_match (buffer->name, ptr_filter->buffer_name, 0))
             {
                 if ((strcmp (ptr_filter->tags, "*") == 0)
-                    || (gui_chat_line_match_tags (line,
-                                                  ptr_filter->tags_count,
-                                                  ptr_filter->tags_array)))
+                    || (gui_line_match_tags (line,
+                                             ptr_filter->tags_count,
+                                             ptr_filter->tags_array)))
                 {
                     /* check line with regex */
                     if (!ptr_filter->regex_prefix && !ptr_filter->regex_message)
                         return 0;
                     
-                    if (gui_chat_line_match_regex (line,
-                                                   ptr_filter->regex_prefix,
-                                                   ptr_filter->regex_message))
+                    if (gui_line_match_regex (line,
+                                              ptr_filter->regex_prefix,
+                                              ptr_filter->regex_message))
                         return 0;
                 }
             }
@@ -125,32 +125,32 @@ gui_filter_buffer (struct t_gui_buffer *buffer)
     
     lines_hidden = 0;
     
-    buffer->prefix_max_length = 0;
+    buffer->lines->prefix_max_length = 0;
     
-    for (ptr_line = buffer->lines; ptr_line;
+    for (ptr_line = buffer->lines->first_line; ptr_line;
          ptr_line = ptr_line->next_line)
     {
         line_displayed = gui_filter_check_line (buffer, ptr_line);
         
         if (line_displayed
-            && (ptr_line->prefix_length > buffer->prefix_max_length))
+            && (ptr_line->data->prefix_length > buffer->lines->prefix_max_length))
         {
-            buffer->prefix_max_length = ptr_line->prefix_length;
+            buffer->lines->prefix_max_length = ptr_line->data->prefix_length;
         }
         
         /* force chat refresh if at least one line changed */
-        if (ptr_line->displayed != line_displayed)
+        if (ptr_line->data->displayed != line_displayed)
             gui_buffer_ask_chat_refresh (buffer, 2);
         
-        ptr_line->displayed = line_displayed;
+        ptr_line->data->displayed = line_displayed;
         
         if (!line_displayed)
             lines_hidden = 1;
     }
     
-    if (buffer->lines_hidden != lines_hidden)
+    if (buffer->lines->lines_hidden != lines_hidden)
     {
-        buffer->lines_hidden = lines_hidden;
+        buffer->lines->lines_hidden = lines_hidden;
         hook_signal_send ("buffer_lines_hidden",
                           WEECHAT_HOOK_SIGNAL_POINTER, buffer);
     }
diff --git a/src/gui/gui-hotlist.c b/src/gui/gui-hotlist.c
index ae14bb5d3..2d8cf38fb 100644
--- a/src/gui/gui-hotlist.c
+++ b/src/gui/gui-hotlist.c
@@ -293,7 +293,8 @@ gui_hotlist_add (struct t_gui_buffer *buffer, int priority,
     if (!gui_hotlist_check_buffer_notify (buffer, priority))
         return;
     
-    if ((ptr_hotlist = gui_hotlist_search (gui_hotlist, buffer)))
+    ptr_hotlist = gui_hotlist_search (gui_hotlist, buffer);
+    if (ptr_hotlist)
     {
         /* return if priority is greater or equal than the one to add */
         if (ptr_hotlist->priority >= priority)
@@ -395,7 +396,7 @@ void
 gui_hotlist_remove_buffer (struct t_gui_buffer *buffer)
 {
     struct t_gui_hotlist *pos_hotlist;
-
+    
     pos_hotlist = gui_hotlist_search (gui_hotlist, buffer);
     if (pos_hotlist)
     {
@@ -453,6 +454,10 @@ gui_hotlist_add_to_infolist (struct t_infolist *infolist,
         return 0;
     if (!infolist_new_var_integer (ptr_item, "buffer_number", hotlist->buffer->number))
         return 0;
+    if (!infolist_new_var_string (ptr_item, "plugin_name", plugin_get_name (hotlist->buffer->plugin)))
+        return 0;
+    if (!infolist_new_var_string (ptr_item, "buffer_name", hotlist->buffer->name))
+        return 0;
     
     return 1;
 }
diff --git a/src/gui/gui-input.c b/src/gui/gui-input.c
index 645ac945b..2429f31eb 100644
--- a/src/gui/gui-input.c
+++ b/src/gui/gui-input.c
@@ -35,11 +35,11 @@
 #include "../plugins/plugin.h"
 #include "gui-input.h"
 #include "gui-buffer.h"
-#include "gui-chat.h"
 #include "gui-completion.h"
 #include "gui-history.h"
 #include "gui-hotlist.h"
 #include "gui-keyboard.h"
+#include "gui-line.h"
 #include "gui-window.h"
 
 
@@ -1239,17 +1239,17 @@ gui_input_scroll_unread ()
         if (CONFIG_STRING(config_look_read_marker) &&
             CONFIG_STRING(config_look_read_marker)[0] &&
             (gui_current_window->buffer->type == GUI_BUFFER_TYPE_FORMATTED) &&
-            (gui_current_window->buffer->first_line_not_read ||
-             (gui_current_window->buffer->last_read_line &&
-              gui_current_window->buffer->last_read_line != gui_current_window->buffer->last_line)))
+            (gui_current_window->buffer->lines->first_line_not_read ||
+             (gui_current_window->buffer->lines->last_read_line &&
+              gui_current_window->buffer->lines->last_read_line != gui_current_window->buffer->lines->last_line)))
         {
-            if (gui_current_window->buffer->first_line_not_read)
-                gui_current_window->start_line = gui_current_window->buffer->lines;
+            if (gui_current_window->buffer->lines->first_line_not_read)
+                gui_current_window->start_line = gui_current_window->buffer->lines->first_line;
             else
-                gui_current_window->start_line = gui_current_window->buffer->last_read_line->next_line;
+                gui_current_window->start_line = gui_current_window->buffer->lines->last_read_line->next_line;
             gui_current_window->start_line_pos = 0;
             gui_current_window->first_line_displayed =
-                (gui_current_window->start_line == gui_chat_get_first_line_displayed (gui_current_window->buffer));
+                (gui_current_window->start_line == gui_line_get_first_displayed (gui_current_window->buffer));
             gui_buffer_ask_chat_refresh (gui_current_window->buffer, 2);
         }
     }
@@ -1285,6 +1285,24 @@ gui_input_set_unread_current_buffer ()
 }
 
 /*
+ * gui_input_switch_active_buffer: switch active buffer (when many buffers are
+ *                                 merged)
+ */
+
+void
+gui_input_switch_active_buffer ()
+{
+    struct t_gui_buffer *ptr_buffer;
+    
+    ptr_buffer = gui_buffer_get_next_active_buffer (gui_current_window->buffer);
+    if (ptr_buffer)
+    {
+        gui_buffer_set_active_buffer (ptr_buffer);
+        gui_window_switch_to_buffer (gui_current_window, ptr_buffer, 1);
+    }
+}
+
+/*
  * gui_input_insert: insert a string in command line
  *                   (many default keys are bound to this function)
  */
diff --git a/src/gui/gui-input.h b/src/gui/gui-input.h
index dcbcc3e67..0a1e4983d 100644
--- a/src/gui/gui-input.h
+++ b/src/gui/gui-input.h
@@ -66,6 +66,7 @@ extern void gui_input_grab_key ();
 extern void gui_input_scroll_unread ();
 extern void gui_input_set_unread ();
 extern void gui_input_set_unread_current_buffer ();
+extern void gui_input_switch_active_buffer ();
 extern void gui_input_insert ();
 
 #endif /* gui-input.h */
diff --git a/src/gui/gui-line.c b/src/gui/gui-line.c
new file mode 100644
index 000000000..b73d75805
--- /dev/null
+++ b/src/gui/gui-line.c
@@ -0,0 +1,1068 @@
+/*
+ * Copyright (c) 2003-2009 by FlashCode <flashcode@flashtux.org>
+ * See README for License detail, AUTHORS for developers list.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* gui-line.c: line functions, used by all GUI */
+
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "../core/weechat.h"
+#include "../core/wee-config.h"
+#include "../core/wee-hook.h"
+#include "../core/wee-infolist.h"
+#include "../core/wee-log.h"
+#include "../core/wee-string.h"
+#include "../plugins/plugin.h"
+#include "gui-line.h"
+#include "gui-buffer.h"
+#include "gui-chat.h"
+#include "gui-color.h"
+#include "gui-filter.h"
+#include "gui-hotlist.h"
+#include "gui-window.h"
+
+
+/*
+ * gui_lines_alloc: alloc structure "t_gui_lines" and initialize it
+ */
+
+struct t_gui_lines *
+gui_lines_alloc ()
+{
+    struct t_gui_lines *new_lines;
+
+    new_lines = malloc (sizeof (*new_lines));
+    if (new_lines)
+    {
+        new_lines->first_line = NULL;
+        new_lines->last_line = NULL;
+        new_lines->last_read_line = NULL;
+        new_lines->lines_count = 0;
+        new_lines->first_line_not_read = 0;
+        new_lines->lines_hidden = 0;
+        new_lines->buffer_max_length = 0;
+        new_lines->prefix_max_length = 0;
+    }
+    
+    return new_lines;
+}
+
+/*
+ * gui_lines_free: free a "t_gui_lines" structure
+ */
+
+void
+gui_lines_free (struct t_gui_lines *lines)
+{
+    free (lines);
+}
+
+/*
+ * gui_line_get_align: get alignment for a line
+ */
+
+int
+gui_line_get_align (struct t_gui_buffer *buffer, struct t_gui_line *line,
+                    int with_suffix)
+{
+    int length_time, length_buffer, length_suffix;
+    
+    /* length of time */
+    length_time = (buffer->time_for_each_line) ? gui_chat_time_length : 0;
+    
+    /* length of buffer name (when many buffers are merged) */
+    if (buffer->mixed_lines)
+    {
+        length_buffer = ((CONFIG_INTEGER(config_look_prefix_buffer_align) == CONFIG_LOOK_PREFIX_ALIGN_NONE)
+                         && (CONFIG_INTEGER(config_look_prefix_align) == CONFIG_LOOK_PREFIX_ALIGN_NONE)) ?
+            gui_chat_strlen_screen (buffer->short_name) + 1 : buffer->mixed_lines->buffer_max_length + 1;
+    }
+    else
+        length_buffer = 0;
+    
+    if (CONFIG_INTEGER(config_look_prefix_align) == CONFIG_LOOK_PREFIX_ALIGN_NONE)
+        return length_time + 1 + length_buffer + line->data->prefix_length + 2;
+    
+    length_suffix = 0;
+    if (with_suffix)
+    {
+        if (CONFIG_STRING(config_look_prefix_suffix)
+            && CONFIG_STRING(config_look_prefix_suffix)[0])
+            length_suffix = gui_chat_strlen_screen (CONFIG_STRING(config_look_prefix_suffix)) + 1;
+    }
+    
+    return length_time + ((buffer->lines->prefix_max_length > 0) ? 1 : 0)
+        + length_buffer
+        + (((CONFIG_INTEGER(config_look_prefix_align_max) > 0)
+            && (buffer->lines->prefix_max_length > CONFIG_INTEGER(config_look_prefix_align_max))) ?
+           CONFIG_INTEGER(config_look_prefix_align_max) : buffer->lines->prefix_max_length)
+        + length_suffix + 1;
+}
+
+/*
+ * gui_line_is_displayed: return 1 if line is displayed (no filter on line,
+ *                        or filters disabled), 0 if line is hidden
+ */
+
+int
+gui_line_is_displayed (struct t_gui_line *line)
+{
+    /* line is hidden if filters are enabled and flag "displayed" is not set */
+    if (gui_filters_enabled && !line->data->displayed)
+        return 0;
+    
+    /* in all other cases, line is displayed */
+    return 1;
+}
+
+/*
+ * gui_line_get_first_displayed: get first line displayed of a buffer
+ */
+
+struct t_gui_line *
+gui_line_get_first_displayed (struct t_gui_buffer *buffer)
+{
+    struct t_gui_line *ptr_line;
+    
+    ptr_line = buffer->lines->first_line;
+    while (ptr_line && !gui_line_is_displayed (ptr_line))
+    {
+        ptr_line = ptr_line->next_line;
+    }
+    
+    return ptr_line;
+}
+
+/*
+ * gui_line_get_last_displayed: get last line displayed of a buffer
+ */
+
+struct t_gui_line *
+gui_line_get_last_displayed (struct t_gui_buffer *buffer)
+{
+    struct t_gui_line *ptr_line;
+    
+    ptr_line = buffer->lines->last_line;
+    while (ptr_line && !gui_line_is_displayed (ptr_line))
+    {
+        ptr_line = ptr_line->prev_line;
+    }
+    
+    return ptr_line;
+}
+
+/*
+ * gui_line_get_prev_displayed: get previous line displayed
+ */
+
+struct t_gui_line *
+gui_line_get_prev_displayed (struct t_gui_line *line)
+{
+    if (line)
+    {
+        line = line->prev_line;
+        while (line && !gui_line_is_displayed (line))
+        {
+            line = line->prev_line;
+        }
+    }
+    return line;
+}
+
+/*
+ * gui_line_get_next_displayed: get next line displayed
+ */
+
+struct t_gui_line *
+gui_line_get_next_displayed (struct t_gui_line *line)
+{
+    if (line)
+    {
+        line = line->next_line;
+        while (line && !gui_line_is_displayed (line))
+        {
+            line = line->next_line;
+        }
+    }
+    return line;
+}
+
+/*
+ * gui_line_search_text: search for text in a line
+ */
+
+int
+gui_line_search_text (struct t_gui_line *line, const char *text,
+                      int case_sensitive)
+{
+    char *prefix, *message;
+    int rc;
+    
+    if (!line || !line->data->message || !text || !text[0])
+        return 0;
+    
+    rc = 0;
+    
+    if (line->data->prefix)
+    {
+        prefix = gui_color_decode (line->data->prefix, NULL);
+        if (prefix)
+        {
+            if ((case_sensitive && (strstr (prefix, text)))
+                || (!case_sensitive && (string_strcasestr (prefix, text))))
+                rc = 1;
+            free (prefix);
+        }
+    }
+    
+    if (!rc)
+    {
+        message = gui_color_decode (line->data->message, NULL);
+        if (message)
+        {
+            if ((case_sensitive && (strstr (message, text)))
+                || (!case_sensitive && (string_strcasestr (message, text))))
+                rc = 1;
+            free (message);
+        }
+    }
+    
+    return rc;
+}
+
+/*
+ * gui_line_match_regex: return 1 if message matches regex
+ *                       0 if it doesn't match
+ */
+
+int
+gui_line_match_regex (struct t_gui_line *line, regex_t *regex_prefix,
+                      regex_t *regex_message)
+{
+    char *prefix, *message;
+    int match_prefix, match_message;
+    
+    if (!line || (!regex_prefix && !regex_message))
+        return 0;
+    
+    prefix = NULL;
+    message = NULL;
+    
+    match_prefix = 1;
+    match_message = 1;
+
+    if (line->data->prefix)
+    {
+        prefix = gui_color_decode (line->data->prefix, NULL);
+        if (!prefix
+            || (regex_prefix && (regexec (regex_prefix, prefix, 0, NULL, 0) != 0)))
+            match_prefix = 0;
+    }
+    else
+    {
+        if (regex_prefix)
+            match_prefix = 0;
+    }
+
+    if (line->data->message)
+    {
+        message = gui_color_decode (line->data->message, NULL);
+        if (!message
+            || (regex_message && (regexec (regex_message, message, 0, NULL, 0) != 0)))
+            match_message = 0;
+    }
+    else
+    {
+        if (regex_message)
+            match_message = 0;
+    }
+    
+    if (prefix)
+        free (prefix);
+    if (message)
+        free (message);
+    
+    return (match_prefix && match_message);
+}
+
+/*
+ * gui_line_match_tags: return 1 if line matches tags
+ *                      0 if it doesn't match any tag in array
+ */
+
+int
+gui_line_match_tags (struct t_gui_line *line, int tags_count,
+                     char **tags_array)
+{
+    int i, j;
+    
+    if (!line)
+        return 0;
+    
+    if (line->data->tags_count == 0)
+        return 0;
+    
+    for (i = 0; i < tags_count; i++)
+    {
+        for (j = 0; j < line->data->tags_count; j++)
+        {
+            /* check tag */
+            if (string_match (line->data->tags_array[j],
+                              tags_array[i],
+                              0))
+                return 1;
+        }
+    }
+    
+    return 0;
+}
+
+/*
+ * gui_line_has_highlight: return 1 if given message contains highlight (with
+ *                         a string in global highlight or buffer highlight)
+ */
+
+int
+gui_line_has_highlight (struct t_gui_line *line)
+{
+    int rc, i;
+    char *msg_no_color;
+    
+    /* highlights are disabled on this buffer? (special value "-" means that
+       buffer does not want any highlight) */
+    if (line->data->buffer->highlight_words
+        && (strcmp (line->data->buffer->highlight_words, "-") == 0))
+        return 0;
+    
+    /* check if highlight is disabled for line */
+    for (i = 0; i < line->data->tags_count; i++)
+    {
+        if (strcmp (line->data->tags_array[i], GUI_CHAT_TAG_NO_HIGHLIGHT) == 0)
+            return 0;
+    }
+    
+    /* check that line matches highlight tags, if any (if no tag is specified,
+       then any tag is allowed) */
+    if (line->data->buffer->highlight_tags_count > 0)
+    {
+        if (!gui_line_match_tags (line,
+                                  line->data->buffer->highlight_tags_count,
+                                  line->data->buffer->highlight_tags_array))
+            return 0;
+    }
+    
+    /* remove color codes from line message */
+    msg_no_color = gui_color_decode (line->data->message, NULL);
+    if (!msg_no_color)
+        return 0;
+    
+    /* there is highlight on line if one of global highlight words matches line
+       or one of buffer highlight words matches line */
+    rc = (string_has_highlight (msg_no_color,
+                                CONFIG_STRING(config_look_highlight)) ||
+          string_has_highlight (msg_no_color,
+                                line->data->buffer->highlight_words));
+    
+    free (msg_no_color);
+    
+    return rc;
+}
+
+/*
+ * gui_line_compute_buffer_max_length: compute "buffer_max_length" for a
+ *                                     "t_gui_lines" structure
+ */
+
+void
+gui_line_compute_buffer_max_length (struct t_gui_buffer *buffer,
+                                    struct t_gui_lines *lines)
+{
+    struct t_gui_buffer *ptr_buffer;
+    int length;
+    
+    lines->buffer_max_length = 0;
+    for (ptr_buffer = gui_buffers; ptr_buffer;
+         ptr_buffer = ptr_buffer->next_buffer)
+    {
+        if ((ptr_buffer->number == buffer->number) && ptr_buffer->short_name)
+        {
+            length = gui_chat_strlen_screen (ptr_buffer->short_name);
+            if (length > lines->buffer_max_length)
+                lines->buffer_max_length = length;
+        }
+    }
+}
+
+/*
+ * gui_line_compute_prefix_max_length: compute "prefix_max_length" for a
+ *                                     "t_gui_lines" structure
+ */
+
+void
+gui_line_compute_prefix_max_length (struct t_gui_lines *lines)
+{
+    struct t_gui_line *ptr_line;
+    
+    lines->prefix_max_length = 0;
+    for (ptr_line = lines->first_line; ptr_line;
+         ptr_line = ptr_line->next_line)
+    {
+        if (ptr_line->data->prefix_length > lines->prefix_max_length)
+            lines->prefix_max_length = ptr_line->data->prefix_length;
+    }
+}
+
+/*
+ * gui_line_add_to_list: add a line to a "t_gui_lines" structure
+ */
+
+void
+gui_line_add_to_list (struct t_gui_lines *lines,
+                      struct t_gui_line *line)
+{
+    if (!lines->first_line)
+        lines->first_line = line;
+    else
+        (lines->last_line)->next_line = line;
+    line->prev_line = lines->last_line;
+    line->next_line = NULL;
+    lines->last_line = line;
+    
+    if (line->data->prefix_length > lines->prefix_max_length)
+        lines->prefix_max_length = line->data->prefix_length;
+    
+    lines->lines_count++;
+}
+
+/*
+ * gui_line_remove_from_list: remove a line from a "t_gui_lines" structure
+ */
+
+void
+gui_line_remove_from_list (struct t_gui_lines *lines,
+                           struct t_gui_line *line,
+                           int free_data)
+{
+    int update_prefix_max_length;
+    
+    update_prefix_max_length =
+        (line->data->prefix_length == lines->prefix_max_length);
+    
+    /* free data */
+    if (free_data)
+    {
+        if (line->data->str_time)
+            free (line->data->str_time);
+        if (line->data->tags_array)
+            string_free_exploded (line->data->tags_array);
+        if (line->data->prefix)
+            free (line->data->prefix);
+        if (line->data->message)
+            free (line->data->message);
+        free (line->data);
+    }
+    
+    /* remove line from list */
+    if (line->prev_line)
+        (line->prev_line)->next_line = line->next_line;
+    if (line->next_line)
+        (line->next_line)->prev_line = line->prev_line;
+    if (lines->first_line == line)
+        lines->first_line = line->next_line;
+    if (lines->last_line == line)
+        lines->last_line = line->prev_line;
+    
+    lines->lines_count--;
+    
+    free (line);
+    
+    /* compute "prefix_max_length" if needed */
+    if (update_prefix_max_length)
+        gui_line_compute_prefix_max_length (lines);
+}
+
+/*
+ * gui_line_mixed_add: add line to mixed lines for a buffer
+ */
+
+void
+gui_line_mixed_add (struct t_gui_lines *lines,
+                    struct t_gui_line_data *line_data)
+{
+    struct t_gui_line *new_line;
+    
+    new_line = malloc (sizeof (*new_line));
+    if (new_line)
+    {
+        new_line->data = line_data;
+        gui_line_add_to_list (lines, new_line);
+    }
+}
+
+/*
+ * gui_line_mixed_free_buffer: free all mixed lines matching a buffer
+ */
+
+void
+gui_line_mixed_free_buffer (struct t_gui_buffer *buffer)
+{
+    struct t_gui_line *ptr_line, *ptr_next_line;
+    
+    if (buffer->mixed_lines)
+    {
+        ptr_line = buffer->mixed_lines->first_line;
+        while (ptr_line)
+        {
+            ptr_next_line = ptr_line->next_line;
+            
+            if (ptr_line->data->buffer == buffer)
+            {
+                gui_line_remove_from_list (buffer->mixed_lines,
+                                           ptr_line,
+                                           0);
+            }
+            
+            ptr_line = ptr_next_line;
+        }
+    }
+}
+
+/*
+ * gui_line_mixed_free_all: free all mixed lines in a buffer
+ */
+
+void
+gui_line_mixed_free_all (struct t_gui_buffer *buffer)
+{
+    if (buffer->mixed_lines)
+    {
+        while (buffer->mixed_lines->first_line)
+        {
+            gui_line_remove_from_list (buffer->mixed_lines,
+                                       buffer->mixed_lines->first_line,
+                                       0);
+        }
+    }
+}
+
+/*
+ * gui_line_free: delete a formatted line from a buffer
+ */
+
+void
+gui_line_free (struct t_gui_buffer *buffer, struct t_gui_line *line)
+{
+    struct t_gui_line *ptr_line;
+    struct t_gui_window *ptr_win;
+    
+    /* first remove mixed line if it exists */
+    if (buffer->mixed_lines)
+    {
+        for (ptr_line = buffer->mixed_lines->first_line; ptr_line;
+             ptr_line = ptr_line->next_line)
+        {
+            if (ptr_line->data == line->data)
+            {
+                gui_line_remove_from_list (buffer->mixed_lines, ptr_line, 0);
+                break;
+            }
+        }
+    }
+    
+    /* reset scroll for any window starting with this line */
+    for (ptr_win = gui_windows; ptr_win; ptr_win = ptr_win->next_window)
+    {
+        if (ptr_win->start_line == line)
+        {
+            ptr_win->start_line = ptr_win->start_line->next_line;
+            ptr_win->start_line_pos = 0;
+            gui_buffer_ask_chat_refresh (buffer, 2);
+        }
+    }
+    
+    /* move read marker if it was on line we are removing */
+    if (buffer->own_lines->last_read_line == line)
+    {
+        buffer->own_lines->last_read_line = buffer->own_lines->last_read_line->prev_line;
+        buffer->own_lines->first_line_not_read = (buffer->own_lines->last_read_line) ? 0 : 1;
+        gui_buffer_ask_chat_refresh (buffer, 1);
+    }
+    
+    /* remove line from lines list */
+    gui_line_remove_from_list (buffer->own_lines, line, 1);
+}
+
+/*
+ * gui_line_free_all: delete all formatted lines from a buffer
+ */
+
+void
+gui_line_free_all (struct t_gui_buffer *buffer)
+{
+    while (buffer->own_lines->first_line)
+    {
+        gui_line_free (buffer, buffer->own_lines->first_line);
+    }
+}
+
+/*
+ * gui_line_get_notify_level: get notify level for a line
+ */
+
+int
+gui_line_get_notify_level (struct t_gui_line *line)
+{
+    int i;
+    
+    for (i = 0; i < line->data->tags_count; i++)
+    {
+        if (string_strcasecmp (line->data->tags_array[i], "notify_highlight") == 0)
+            return GUI_HOTLIST_HIGHLIGHT;
+        if (string_strcasecmp (line->data->tags_array[i], "notify_private") == 0)
+            return GUI_HOTLIST_PRIVATE;
+        if (string_strcasecmp (line->data->tags_array[i], "notify_message") == 0)
+            return GUI_HOTLIST_MESSAGE;
+    }
+    return GUI_HOTLIST_LOW;
+}
+
+/*
+ * gui_line_add: add a new line for a buffer
+ */
+
+struct t_gui_line *
+gui_line_add (struct t_gui_buffer *buffer, time_t date,
+              time_t date_printed, const char *tags,
+              const char *prefix, const char *message)
+{
+    struct t_gui_line *new_line;
+    struct t_gui_line_data *new_line_data;
+    struct t_gui_window *ptr_win;
+    char *message_for_signal;
+    int notify_level;
+    
+    new_line = malloc (sizeof (*new_line));
+    if (!new_line)
+    {
+        log_printf (_("Not enough memory for new line"));
+        return NULL;
+    }
+    
+    new_line_data = malloc (sizeof (*(new_line->data)));
+    if (!new_line_data)
+    {
+        free (new_line);
+        log_printf (_("Not enough memory for new line"));
+        return NULL;
+    }
+    new_line->data = new_line_data;
+    
+    /* fill data in new line */
+    new_line->data->buffer = buffer;
+    new_line->data->y = 0;
+    new_line->data->date = date;
+    new_line->data->date_printed = date_printed;
+    new_line->data->str_time = (date == 0) ?
+        NULL : gui_chat_get_time_string (date);
+    if (tags)
+    {
+        new_line->data->tags_array = string_explode (tags, ",", 0, 0,
+                                                     &new_line->data->tags_count);
+    }
+    else
+    {
+        new_line->data->tags_count = 0;
+        new_line->data->tags_array = NULL;
+    }
+    new_line->data->refresh_needed = 0;
+    new_line->data->prefix = (prefix) ?
+        strdup (prefix) : ((date != 0) ? strdup ("") : NULL);
+    new_line->data->prefix_length = (prefix) ?
+        gui_chat_strlen_screen (prefix) : 0;
+    new_line->data->message = (message) ? strdup (message) : strdup ("");
+    new_line->data->highlight = gui_line_has_highlight (new_line);
+    
+    /* add line to lines list */
+    gui_line_add_to_list (buffer->own_lines, new_line);
+    
+    /* check if line is filtered or not */
+    new_line->data->displayed = gui_filter_check_line (buffer, new_line);
+    if (new_line->data->displayed)
+    {
+        if (new_line->data->highlight)
+        {
+            gui_hotlist_add (buffer, GUI_HOTLIST_HIGHLIGHT, NULL, 1);
+            if (!weechat_upgrading)
+            {
+                message_for_signal = gui_chat_build_string_prefix_message (new_line);
+                if (message_for_signal)
+                {
+                    hook_signal_send ("weechat_highlight",
+                                      WEECHAT_HOOK_SIGNAL_STRING,
+                                      message_for_signal);
+                    free (message_for_signal);
+                }
+            }
+        }
+        else
+        {
+            notify_level = gui_line_get_notify_level (new_line);
+            if (!weechat_upgrading && (notify_level == GUI_HOTLIST_PRIVATE))
+            {
+                message_for_signal = gui_chat_build_string_prefix_message (new_line);
+                if (message_for_signal)
+                {
+                    hook_signal_send ("weechat_pv",
+                                      WEECHAT_HOOK_SIGNAL_STRING,
+                                      message_for_signal);
+                    free (message_for_signal);
+                }
+            }
+            gui_hotlist_add (buffer, notify_level, NULL, 1);
+        }
+    }
+    else
+    {
+        if (!buffer->own_lines->lines_hidden)
+        {
+            buffer->own_lines->lines_hidden = 1;
+            if (buffer->mixed_lines)
+                buffer->mixed_lines->lines_hidden = 1;
+            hook_signal_send ("buffer_lines_hidden",
+                              WEECHAT_HOOK_SIGNAL_POINTER, buffer);
+        }
+    }
+    
+    /* add mixed line, if buffer is attched to at least one other buffer */
+    if (buffer->mixed_lines)
+    {
+        gui_line_mixed_add (buffer->mixed_lines, new_line->data);
+    }
+    
+    /* remove one line if necessary */
+    if ((CONFIG_INTEGER(config_history_max_lines) > 0)
+        && (buffer->own_lines->lines_count > CONFIG_INTEGER(config_history_max_lines)))
+    {
+        gui_line_free (buffer, buffer->own_lines->first_line);
+        for (ptr_win = gui_windows; ptr_win; ptr_win = ptr_win->next_window)
+        {
+            if ((ptr_win->buffer == buffer)
+                && (buffer->own_lines->lines_count < ptr_win->win_chat_height))
+            {
+                gui_buffer_ask_chat_refresh (buffer, 2);
+                break;
+            }
+        }
+    }
+    
+    return new_line;
+}
+
+/*
+ * gui_line_add_y: add or update a line for a buffer with free content
+ */
+
+void
+gui_line_add_y (struct t_gui_buffer *buffer, int y, const char *message)
+{
+    struct t_gui_line *ptr_line, *new_line;
+    struct t_gui_line_data *new_line_data;
+    
+    if (!message || !message[0])
+        return;
+    
+    /* search if line exists for "y" */
+    for (ptr_line = buffer->own_lines->first_line; ptr_line;
+         ptr_line = ptr_line->next_line)
+    {
+        if (ptr_line->data->y >= y)
+            break;
+    }
+    
+    if (!ptr_line || (ptr_line->data->y > y))
+    {
+        new_line = malloc (sizeof (*new_line));
+        if (!new_line)
+        {
+            log_printf (_("Not enough memory for new line"));
+            return;
+        }
+        
+        new_line_data = malloc (sizeof (*(new_line->data)));
+        if (!new_line_data)
+        {
+            free (new_line);
+            log_printf (_("Not enough memory for new line"));
+            return;
+        }
+        new_line->data = new_line_data;
+        
+        buffer->own_lines->lines_count++;
+        
+        /* fill data in new line */
+        new_line->data->y = y;
+        new_line->data->date = 0;
+        new_line->data->date_printed = 0;
+        new_line->data->str_time = NULL;
+        new_line->data->tags_count = 0;
+        new_line->data->tags_array = NULL;
+        new_line->data->refresh_needed = 1;
+        new_line->data->prefix = NULL;
+        new_line->data->prefix_length = 0;
+        new_line->data->message = NULL;
+        new_line->data->highlight = 0;
+        
+        /* add line to lines list */
+        if (ptr_line)
+        {
+            /* add before line found */
+            new_line->prev_line = ptr_line->prev_line;
+            new_line->next_line = ptr_line;
+            if (ptr_line->prev_line)
+                (ptr_line->prev_line)->next_line = new_line;
+            else
+                buffer->own_lines->first_line = new_line;
+            ptr_line->prev_line = new_line;
+        }
+        else
+        {
+            /* add at end of list */
+            new_line->prev_line = buffer->own_lines->last_line;
+            if (buffer->own_lines->first_line)
+                buffer->own_lines->last_line->next_line = new_line;
+            else
+                buffer->own_lines->first_line = new_line;
+            buffer->own_lines->last_line = new_line;
+            new_line->next_line = NULL;
+        }
+
+        ptr_line = new_line;
+    }
+    
+    /* set message for line */
+    if (ptr_line->data->message)
+        free (ptr_line->data->message);
+    ptr_line->data->message = strdup (message);
+    
+    /* check if line is filtered or not */
+    ptr_line->data->displayed = gui_filter_check_line (buffer, ptr_line);
+    if (!ptr_line->data->displayed)
+    {
+        if (!buffer->own_lines->lines_hidden)
+        {
+            buffer->own_lines->lines_hidden = 1;
+            hook_signal_send ("buffer_lines_hidden",
+                              WEECHAT_HOOK_SIGNAL_POINTER, buffer);
+        }
+    }
+    
+    ptr_line->data->refresh_needed = 1;
+}
+
+/*
+ * gui_line_mix_buffers: mix lines of a buffer (or group of buffers) with a new
+ *                       buffer
+ */
+
+void
+gui_line_mix_buffers (struct t_gui_buffer *buffer)
+{
+    struct t_gui_buffer *ptr_buffer, *ptr_buffer_found;
+    struct t_gui_lines *new_lines;
+    struct t_gui_line *ptr_line1, *ptr_line2;
+    
+    /* search first other buffer with same number */
+    ptr_buffer_found = NULL;
+    for (ptr_buffer = gui_buffers; ptr_buffer;
+         ptr_buffer = ptr_buffer->next_buffer)
+    {
+        if ((ptr_buffer != buffer) && (ptr_buffer->number == buffer->number))
+        {
+            ptr_buffer_found = ptr_buffer;
+            break;
+        }
+    }
+    if (!ptr_buffer_found)
+        return;
+    
+    /* mix all lines (sorting by date) to a new structure "new_lines" */
+    new_lines = gui_lines_alloc ();
+    if (!new_lines)
+        return;
+    ptr_line1 = ptr_buffer_found->lines->first_line;
+    ptr_line2 = buffer->lines->first_line;
+    while (ptr_line1 || ptr_line2)
+    {
+        if (!ptr_line1)
+        {
+            gui_line_mixed_add (new_lines, ptr_line2->data);
+            ptr_line2 = ptr_line2->next_line;
+        }
+        else
+        {
+            if (!ptr_line2)
+            {
+                gui_line_mixed_add (new_lines, ptr_line1->data);
+                ptr_line1 = ptr_line1->next_line;
+            }
+            else
+            {
+                /* look for older line by comparing time */
+                if (ptr_line1->data->date <= ptr_line2->data->date)
+                {
+                    while (ptr_line1
+                           && (ptr_line1->data->date <= ptr_line2->data->date))
+                    {
+                        gui_line_mixed_add (new_lines, ptr_line1->data);
+                        ptr_line1 = ptr_line1->next_line;
+                    }
+                }
+                else
+                {
+                    while (ptr_line2
+                           && (ptr_line1->data->date > ptr_line2->data->date))
+                    {
+                        gui_line_mixed_add (new_lines, ptr_line2->data);
+                        ptr_line2 = ptr_line2->next_line;
+                    }
+                }
+            }
+        }
+    }
+    
+    /* compute "prefix_max_length" for mixed lines */
+    gui_line_compute_prefix_max_length (new_lines);
+    
+    /* compute "buffer_max_length" for mixed lines */
+    gui_line_compute_buffer_max_length (buffer, new_lines);
+    
+    /* free old mixed lines */
+    if (ptr_buffer_found->mixed_lines)
+    {
+        gui_line_mixed_free_all (ptr_buffer_found);
+        free (ptr_buffer_found->mixed_lines);
+    }
+    
+    /* use new structure with mixed lines in all buffers with correct number */
+    for (ptr_buffer = gui_buffers; ptr_buffer;
+         ptr_buffer = ptr_buffer->next_buffer)
+    {
+        if (ptr_buffer->number == buffer->number)
+        {
+            ptr_buffer->mixed_lines = new_lines;
+            ptr_buffer->lines = ptr_buffer->mixed_lines;
+        }
+    }
+}
+
+/*
+ * gui_buffer_line_add_to_infolist: add a buffer line in an infolist
+ *                                  return 1 if ok, 0 if error
+ */
+
+int
+gui_line_add_to_infolist (struct t_infolist *infolist,
+                          struct t_gui_lines *lines,
+                          struct t_gui_line *line)
+{
+    struct t_infolist_item *ptr_item;
+    int i, length;
+    char option_name[64], *tags;
+    
+    if (!infolist || !line)
+        return 0;
+    
+    ptr_item = infolist_new_item (infolist);
+    if (!ptr_item)
+        return 0;
+    
+    if (!infolist_new_var_time (ptr_item, "date", line->data->date))
+        return 0;
+    if (!infolist_new_var_time (ptr_item, "date_printed", line->data->date_printed))
+        return 0;
+    if (!infolist_new_var_string (ptr_item, "str_time", line->data->str_time))
+        return 0;
+    
+    /* write tags */
+    if (!infolist_new_var_integer (ptr_item, "tags_count", line->data->tags_count))
+        return 0;
+    length = 0;
+    for (i = 0; i < line->data->tags_count; i++)
+    {
+        snprintf (option_name, sizeof (option_name), "tag_%05d", i + 1);
+        if (!infolist_new_var_string (ptr_item, option_name,
+                                      line->data->tags_array[i]))
+            return 0;
+        length += strlen (line->data->tags_array[i]) + 1;
+    }
+    tags = malloc (length + 1);
+    if (!tags)
+        return 0;
+    tags[0] = '\0';
+    for (i = 0; i < line->data->tags_count; i++)
+    {
+        strcat (tags, line->data->tags_array[i]);
+        if (i < line->data->tags_count - 1)
+            strcat (tags, ",");
+    }
+    if (!infolist_new_var_string (ptr_item, "tags", tags))
+    {
+        free (tags);
+        return 0;
+    }
+    free (tags);
+    
+    if (!infolist_new_var_integer (ptr_item, "displayed", line->data->displayed))
+        return 0;
+    if (!infolist_new_var_integer (ptr_item, "highlight", line->data->highlight))
+        return 0;
+    if (!infolist_new_var_string (ptr_item, "prefix", line->data->prefix))
+        return 0;
+    if (!infolist_new_var_string (ptr_item, "message", line->data->message))
+        return 0;
+    if (!infolist_new_var_integer (ptr_item, "last_read_line",
+                                   (lines->last_read_line == line) ? 1 : 0))
+        return 0;
+    
+    return 1;
+}
+
+/*
+ * gui_lines_print_log: print lines structure infos in log (usually for crash dump)
+ */
+
+void
+gui_lines_print_log (struct t_gui_lines *lines)
+{
+    if (lines)
+    {
+        log_printf ("    first_line . . . . . : 0x%lx", lines->first_line);
+        log_printf ("    last_line. . . . . . : 0x%lx", lines->last_line);
+        log_printf ("    last_read_line . . . : 0x%lx", lines->last_read_line);
+        log_printf ("    lines_count. . . . . . : %d",  lines->lines_count);
+        log_printf ("    first_line_not_read. . : %d",  lines->first_line_not_read);
+        log_printf ("    lines_hidden . . . . : %d",    lines->lines_hidden);
+        log_printf ("    buffer_max_length. . : %d",    lines->buffer_max_length);
+        log_printf ("    prefix_max_length. . : %d",    lines->prefix_max_length);
+    }
+}
diff --git a/src/gui/gui-line.h b/src/gui/gui-line.h
new file mode 100644
index 000000000..fe92716c8
--- /dev/null
+++ b/src/gui/gui-line.h
@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2003-2009 by FlashCode <flashcode@flashtux.org>
+ * See README for License detail, AUTHORS for developers list.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#ifndef __WEECHAT_GUI_LINE_H
+#define __WEECHAT_GUI_LINE_H 1
+
+#include <regex.h>
+
+struct t_infolist;
+
+/* line structures */
+
+struct t_gui_line_data
+{
+    struct t_gui_buffer *buffer;       /* pointer to buffer                 */
+    int y;                             /* line position (for free buffer)   */
+    time_t date;                       /* date/time of line (may be past)   */
+    time_t date_printed;               /* date/time when weechat print it   */
+    char *str_time;                    /* time string (for display)         */
+    int tags_count;                    /* number of tags for line           */
+    char **tags_array;                 /* tags for line                     */
+    char displayed;                    /* 1 if line is displayed            */
+    char highlight;                    /* 1 if line has highlight           */
+    char refresh_needed;               /* 1 if refresh asked (free buffer)  */
+    char *prefix;                      /* prefix for line (may be NULL)     */
+    int prefix_length;                 /* prefix length (on screen)         */
+    char *message;                     /* line content (after prefix)       */
+};
+
+struct t_gui_line
+{
+    struct t_gui_line_data *data;      /* pointer to line data              */
+    struct t_gui_line *prev_line;      /* link to previous line             */
+    struct t_gui_line *next_line;      /* link to next line                 */
+};
+
+struct t_gui_lines
+{
+    struct t_gui_line *first_line;     /* pointer to first line             */
+    struct t_gui_line *last_line;      /* pointer to last line              */
+    struct t_gui_line *last_read_line; /* last read line                    */
+    int lines_count;                   /* number of lines                   */
+    int first_line_not_read;           /* if 1, marker is before first line */
+    int lines_hidden;                  /* 1 if at least one line is hidden  */
+    int buffer_max_length;             /* max length for buffer name (for   */
+                                       /* mixed lines only)                 */
+    int prefix_max_length;             /* max length for prefix align       */
+};
+
+/* line functions */
+
+extern struct t_gui_lines *gui_lines_alloc ();
+extern void gui_lines_free (struct t_gui_lines *lines);
+extern int gui_line_get_align (struct t_gui_buffer *buffer,
+                               struct t_gui_line *line,
+                               int with_suffix);
+extern int gui_line_is_displayed (struct t_gui_line *line);
+extern struct t_gui_line *gui_line_get_first_displayed (struct t_gui_buffer *buffer);
+extern struct t_gui_line *gui_line_get_last_displayed (struct t_gui_buffer *buffer);
+extern struct t_gui_line *gui_line_get_prev_displayed (struct t_gui_line *line);
+extern struct t_gui_line *gui_line_get_next_displayed (struct t_gui_line *line);
+extern int gui_line_search_text (struct t_gui_line *line, const char *text,
+                                 int case_sensitive);
+extern int gui_line_match_regex (struct t_gui_line *line,
+                                 regex_t *regex_prefix,
+                                 regex_t *regex_message);
+extern int gui_line_match_tags (struct t_gui_line *line, int tags_count,
+                                char **tags_array);
+extern int gui_line_has_highlight (struct t_gui_line *line);
+extern void gui_line_mixed_free_buffer (struct t_gui_buffer *buffer);
+extern void gui_line_mixed_free_all (struct t_gui_buffer *buffer);
+extern void gui_line_free (struct t_gui_buffer *buffer,
+                           struct t_gui_line *line);
+extern void gui_line_free_all (struct t_gui_buffer *buffer);
+extern int gui_line_get_notify_level (struct t_gui_line *line);
+extern struct t_gui_line *gui_line_add (struct t_gui_buffer *buffer,
+                                        time_t date,
+                                        time_t date_printed,
+                                        const char *tags,
+                                        const char *prefix,
+                                        const char *message);
+extern void gui_line_add_y (struct t_gui_buffer *buffer, int y,
+                            const char *message);
+extern void gui_line_mix_buffers (struct t_gui_buffer *buffer);
+extern int gui_line_add_to_infolist (struct t_infolist *infolist,
+                                     struct t_gui_lines *lines,
+                                     struct t_gui_line *line);
+extern void gui_lines_print_log (struct t_gui_lines *lines);
+
+#endif /* gui-line.h */
diff --git a/src/gui/gui-window.c b/src/gui/gui-window.c
index 91bd37146..d039c8520 100644
--- a/src/gui/gui-window.c
+++ b/src/gui/gui-window.c
@@ -44,11 +44,11 @@
 #include "gui-bar.h"
 #include "gui-bar-window.h"
 #include "gui-buffer.h"
-#include "gui-chat.h"
 #include "gui-filter.h"
 #include "gui-input.h"
 #include "gui-hotlist.h"
 #include "gui-layout.h"
+#include "gui-line.h"
 
 
 int gui_init_ok = 0;                            /* = 1 if GUI is initialized*/
@@ -419,8 +419,8 @@ gui_window_set_layout_buffer_name (struct t_gui_window *window,
 void
 gui_window_free (struct t_gui_window *window)
 {
-    if (window->buffer && (window->buffer->num_displayed > 0))
-        window->buffer->num_displayed--;
+    if (window->buffer)
+        gui_buffer_add_value_num_displayed (window->buffer, -1);
     
     /* free data */
     if (window->gui_objects)
@@ -524,7 +524,7 @@ gui_window_scroll (struct t_gui_window *window, char *scroll)
     struct t_gui_line *ptr_line;
     struct tm *date_tmp, line_date, old_line_date;
     
-    if (window->buffer->lines)
+    if (window->buffer->lines->first_line)
     {
         direction = 1;
         number = 0;
@@ -579,8 +579,8 @@ gui_window_scroll (struct t_gui_window *window, char *scroll)
         if (direction < 0)
         {
             ptr_line = (window->start_line) ?
-                window->start_line : window->buffer->last_line;
-            while (ptr_line && !gui_chat_line_displayed (ptr_line))
+                window->start_line : window->buffer->lines->last_line;
+            while (ptr_line && !gui_line_is_displayed (ptr_line))
             {
                 ptr_line = ptr_line->prev_line;
             }
@@ -588,21 +588,21 @@ gui_window_scroll (struct t_gui_window *window, char *scroll)
         else
         {
             ptr_line = (window->start_line) ?
-                window->start_line : window->buffer->lines;
-            while (ptr_line && !gui_chat_line_displayed (ptr_line))
+                window->start_line : window->buffer->lines->first_line;
+            while (ptr_line && !gui_line_is_displayed (ptr_line))
             {
                 ptr_line = ptr_line->next_line;
             }
         }
         
-        old_date = ptr_line->date;
+        old_date = ptr_line->data->date;
         date_tmp = localtime (&old_date);
         memcpy (&old_line_date, date_tmp, sizeof (struct tm));
         
         while (ptr_line)
         {
             ptr_line = (direction < 0) ?
-                gui_chat_get_prev_line_displayed (ptr_line) : gui_chat_get_next_line_displayed (ptr_line);
+                gui_line_get_prev_displayed (ptr_line) : gui_line_get_next_displayed (ptr_line);
             
             if (ptr_line)
             {
@@ -614,12 +614,12 @@ gui_window_scroll (struct t_gui_window *window, char *scroll)
                 }
                 else
                 {
-                    date_tmp = localtime (&(ptr_line->date));
+                    date_tmp = localtime (&(ptr_line->data->date));
                     memcpy (&line_date, date_tmp, sizeof (struct tm));
-                    if (old_date > ptr_line->date)
-                        diff_date = old_date - ptr_line->date;
+                    if (old_date > ptr_line->data->date)
+                        diff_date = old_date - ptr_line->data->date;
                     else
-                        diff_date = ptr_line->date - old_date;
+                        diff_date = ptr_line->data->date - old_date;
                     switch (time_letter)
                     {
                         case 's': /* seconds */
@@ -709,7 +709,7 @@ gui_window_scroll (struct t_gui_window *window, char *scroll)
                     window->start_line = ptr_line;
                     window->start_line_pos = 0;
                     window->first_line_displayed =
-                        (window->start_line == gui_chat_get_first_line_displayed (window->buffer));
+                        (window->start_line == gui_line_get_first_displayed (window->buffer));
                     gui_buffer_ask_chat_refresh (window->buffer, 2);
                     return;
                 }
@@ -737,18 +737,18 @@ gui_window_scroll_previous_highlight (struct t_gui_window *window)
     if ((window->buffer->type == GUI_BUFFER_TYPE_FORMATTED)
         && (window->buffer->text_search == GUI_TEXT_SEARCH_DISABLED))
     {
-        if (window->buffer->lines)
+        if (window->buffer->lines->first_line)
         {
             ptr_line = (window->start_line) ?
-                window->start_line->prev_line : window->buffer->last_line;
+                window->start_line->prev_line : window->buffer->lines->last_line;
             while (ptr_line)
             {
-                if (ptr_line->highlight)
+                if (ptr_line->data->highlight)
                 {
                     window->start_line = ptr_line;
                     window->start_line_pos = 0;
                     window->first_line_displayed =
-                        (window->start_line == window->buffer->lines);
+                        (window->start_line == window->buffer->lines->first_line);
                     gui_buffer_ask_chat_refresh (window->buffer, 2);
                     return;
                 }
@@ -770,18 +770,18 @@ gui_window_scroll_next_highlight (struct t_gui_window *window)
     if ((window->buffer->type == GUI_BUFFER_TYPE_FORMATTED)
         && (window->buffer->text_search == GUI_TEXT_SEARCH_DISABLED))
     {
-        if (window->buffer->lines)
+        if (window->buffer->lines->first_line)
         {
             ptr_line = (window->start_line) ?
-                window->start_line->next_line : window->buffer->lines->next_line;
+                window->start_line->next_line : window->buffer->lines->first_line->next_line;
             while (ptr_line)
             {
-                if (ptr_line->highlight)
+                if (ptr_line->data->highlight)
                 {
                     window->start_line = ptr_line;
                     window->start_line_pos = 0;
                     window->first_line_displayed =
-                        (window->start_line == window->buffer->lines);
+                        (window->start_line == window->buffer->lines->first_line);
                     gui_buffer_ask_chat_refresh (window->buffer, 2);
                     return;
                 }
@@ -802,51 +802,51 @@ gui_window_search_text (struct t_gui_window *window)
     
     if (window->buffer->text_search == GUI_TEXT_SEARCH_BACKWARD)
     {
-        if (window->buffer->lines
+        if (window->buffer->lines->first_line
             && window->buffer->input_buffer && window->buffer->input_buffer[0])
         {
             ptr_line = (window->start_line) ?
-                gui_chat_get_prev_line_displayed (window->start_line) :
-                gui_chat_get_last_line_displayed (window->buffer);
+                gui_line_get_prev_displayed (window->start_line) :
+                gui_line_get_last_displayed (window->buffer);
             while (ptr_line)
             {
-                if (gui_chat_line_search (ptr_line,
+                if (gui_line_search_text (ptr_line,
                                           window->buffer->input_buffer,
                                           window->buffer->text_search_exact))
                 {
                     window->start_line = ptr_line;
                     window->start_line_pos = 0;
                     window->first_line_displayed =
-                        (window->start_line == gui_chat_get_first_line_displayed (window->buffer));
+                        (window->start_line == gui_line_get_first_displayed (window->buffer));
                     gui_buffer_ask_chat_refresh (window->buffer, 2);
                     return 1;
                 }
-                ptr_line = gui_chat_get_prev_line_displayed (ptr_line);
+                ptr_line = gui_line_get_prev_displayed (ptr_line);
             }
         }
     }
     else if (window->buffer->text_search == GUI_TEXT_SEARCH_FORWARD)
     {
-        if (window->buffer->lines
+        if (window->buffer->lines->first_line
             && window->buffer->input_buffer && window->buffer->input_buffer[0])
         {
             ptr_line = (window->start_line) ?
-                gui_chat_get_next_line_displayed (window->start_line) :
-                gui_chat_get_first_line_displayed (window->buffer);
+                gui_line_get_next_displayed (window->start_line) :
+                gui_line_get_first_displayed (window->buffer);
             while (ptr_line)
             {
-                if (gui_chat_line_search (ptr_line,
+                if (gui_line_search_text (ptr_line,
                                           window->buffer->input_buffer,
                                           window->buffer->text_search_exact))
                 {
                     window->start_line = ptr_line;
                     window->start_line_pos = 0;
                     window->first_line_displayed =
-                        (window->start_line == window->buffer->lines);
+                        (window->start_line == window->buffer->lines->first_line);
                     gui_buffer_ask_chat_refresh (window->buffer, 2);
                     return 1;
                 }
-                ptr_line = gui_chat_get_next_line_displayed (ptr_line);
+                ptr_line = gui_line_get_next_displayed (ptr_line);
             }
         }
     }
@@ -997,7 +997,7 @@ gui_window_add_to_infolist (struct t_infolist *infolist,
     if (!infolist_new_var_integer (ptr_item, "start_line_y",
                                    ((window->buffer->type == GUI_BUFFER_TYPE_FREE)
                                     && (window->start_line)) ?
-                                   window->start_line->y : 0))
+                                   window->start_line->data->y : 0))
         return 0;
     
     return 1;