core: do not display non printable chars, fix function utf8_char_size_screen

Now the function utf8_char_size_screen can return -1 when the char is not
printable.

It has a specific behavior for some chars:

- U+0009: value of option weechat.look.tab_width
- U+0001 to U+001F (except U+0009): 1
- U+00AD (soft hyphen): -1
- U+200B (zero width space): -1

1 files changed, 1 insertions, 7 deletions

diff --git a/src/gui/curses/gui-curses-bar-window.c b/src/gui/curses/gui-curses-bar-window.c
index 99d64b21b..5d1ea4378 100644
--- a/src/gui/curses/gui-curses-bar-window.c
+++ b/src/gui/curses/gui-curses-bar-window.c
@@ -361,12 +361,6 @@ gui_bar_window_print_string (struct t_gui_bar_window *bar_window,
                     reverse_video = (gui_window_current_color_attr & A_REVERSE) ?
                         0 : 1;
                 }
-                else
-                {
-                    /* display non printable chars as spaces */
-                    if (!gui_chat_utf_char_valid (utf_char))
-                        snprintf (utf_char, sizeof (utf_char), " ");
-                }
 
                 while (ptr_char && ptr_char[0])
                 {
@@ -411,8 +405,8 @@ gui_bar_window_print_string (struct t_gui_bar_window *bar_window,
 
                             *x += size_on_screen;
                         }
-                        ptr_char = utf8_next_char (ptr_char);
                     }
+                    ptr_char = utf8_next_char (ptr_char);
                 }
                 string = utf8_next_char (string);
                 break;