core: add unique "id" in nicklist group and nick (issue #2081)

The id is a "long long" variable with the current time (microseconds
precision).

It is guaranteed to be unique for all groups and nicks inside the buffer, and
the same number is never used again in the same buffer, during the lifetime of
the process.

It persists and is unchanged after `/upgrade`.

23 files changed, 725 insertions, 81 deletions

diff --git a/ChangeLog.adoc b/ChangeLog.adoc
index 687fd203c..1078dcfd6 100644
--- a/ChangeLog.adoc
+++ b/ChangeLog.adoc
@@ -21,7 +21,7 @@ New features::
   * core: add variable `${highlight}` in option weechat.look.buffer_time_format (issue #2079)
   * core: convert option weechat.look.hotlist_sort to a list of fields (issue #2097)
   * core: rename variables with creation time in hdata "hotlist": "creation_time.tv_sec" to "time" and "creation_time.tv_usec" to "time_usec"
-  * core: add unique identifier "id" in buffer (issue #2081)
+  * core: add unique identifier "id" in buffer and nicklist (group and nick) (issue #2081)
   * core: add option `malloc_trim` in command `/sys`
   * core: add support of SGR mouse events (issue #2082)
   * core: reintroduce help on the variables and operators in `/help eval` (issue #2005)
diff --git a/doc/en/weechat_dev.en.adoc b/doc/en/weechat_dev.en.adoc
index b96096e09..86c5561cc 100644
--- a/doc/en/weechat_dev.en.adoc
+++ b/doc/en/weechat_dev.en.adoc
@@ -448,6 +448,7 @@ WeeChat "core" is located in following directories:
 |          test-gui-key.cpp                  | Tests: keys.
 |          test-gui-line.cpp                 | Tests: lines.
 |          test-gui-nick.cpp                 | Tests: nicks.
+|          test-gui-nicklist.cpp             | Tests: nicklist functions.
 |          curses/                           | Root of unit tests for Curses interface.
 |             test-gui-curses-mouse.cpp      | Tests: mouse (Curses interface).
 |       plugins/                             | Root of unit tests for plugins.
diff --git a/doc/en/weechat_plugin_api.en.adoc b/doc/en/weechat_plugin_api.en.adoc
index a5cdf5e84..78405efdb 100644
--- a/doc/en/weechat_plugin_api.en.adoc
+++ b/doc/en/weechat_plugin_api.en.adoc
@@ -14699,6 +14699,7 @@ Arguments:
 ** _short_name_: short name of buffer (note: used for display only and can be changed by user, this must not be used to find name of buffer, use instead _name_, _full_name_ or local variable _channel_)
 ** _type_: type of buffer: "formatted" or "free" _(WeeChat ≥ 4.2.0)_
 ** _title_: title of buffer
+** _nicklist_last_id_assigned_: last unique identifier used in this buffer for a group or nick _(WeeChat ≥ 4.3.0)_
 ** _input_: input text
 ** _text_search_input_: input saved before text search
 ** _highlight_words_: list of words to highlight
@@ -15870,6 +15871,7 @@ Arguments:
 * _buffer_: buffer pointer
 * _group_: group pointer
 * _property_: property name:
+** _id_: unique identifier _(WeeChat ≥ 4.3.0)_
 ** _name_: name of group
 ** _color_: group color in nicklist
 
@@ -16072,6 +16074,7 @@ Arguments:
 * _buffer_: buffer pointer
 * _nick_: nick pointer
 * _property_: property name:
+** _id_: unique identifier _(WeeChat ≥ 4.3.0)_
 ** _name_: name of nick
 ** _color_: nick color in nicklist
 ** _prefix_: prefix of nick
diff --git a/doc/fr/weechat_dev.fr.adoc b/doc/fr/weechat_dev.fr.adoc
index 9ab4fce13..51f8f9415 100644
--- a/doc/fr/weechat_dev.fr.adoc
+++ b/doc/fr/weechat_dev.fr.adoc
@@ -450,6 +450,7 @@ Le cœur de WeeChat est situé dans les répertoires suivants :
 |          test-gui-key.cpp                  | Tests : touches.
 |          test-gui-line.cpp                 | Tests : lignes.
 |          test-gui-nick.cpp                 | Tests : pseudos.
+|          test-gui-nicklist.cpp             | Tests : fonctions de liste de pseudos.
 |          curses/                           | Racine des tests unitaires pour l'interface Curses.
 |             test-gui-curses-mouse.cpp      | Tests : souris (interface Curses).
 |       plugins/                             | Racine des tests unitaires pour les extensions.
diff --git a/doc/fr/weechat_plugin_api.fr.adoc b/doc/fr/weechat_plugin_api.fr.adoc
index ea4acd4e5..ec62d7d9e 100644
--- a/doc/fr/weechat_plugin_api.fr.adoc
+++ b/doc/fr/weechat_plugin_api.fr.adoc
@@ -15016,6 +15016,7 @@ Paramètres :
 ** _short_name_ : nom court du tampon (note : utilisé pour l'affichage seulement et peut être changé par l'utilisateur, il ne doit pas être utilisé pour trouver le nom du tampon, utilisez à la place _name_, _full_name_ ou bien la variable locale _channel_)
 ** _type_ : type de tampon : "formatted" (formaté) ou "free" (contenu libre) _(WeeChat ≥ 4.2.0)_
 ** _title_ : titre du tampon
+** _nicklist_last_id_assigned_ : dernier identifiant unique utilisé dans ce tampon pour un groupe ou un pseudo _(WeeChat ≥ 4.3.0)_
 ** _input_ : texte saisi
 ** _text_search_input_ : texte saisi sauvegardé avant la recherche de texte
 ** _highlight_words_ : liste des mots pour le highlight
@@ -16213,6 +16214,7 @@ Paramètres :
 * _buffer_ : pointeur vers le tampon
 * _group_ : pointeur vers le groupe
 * _property_ : nom de la propriété :
+** _id_ : identifiant unique _(WeeChat ≥ 4.3.0)_
 ** _name_ : nom du groupe
 ** _color_ : couleur du groupe dans la liste des pseudos
 
@@ -16416,6 +16418,7 @@ Paramètres :
 * _buffer_ : pointeur vers le tampon
 * _nick_ : pointeur vers le pseudo
 * _property_ : nom de la propriété :
+** _id_ : identifiant unique _(WeeChat ≥ 4.3.0)_
 ** _name_ : nom du pseudo
 ** _color_ : couleur du pseudo dans la liste des pseudos
 ** _prefix_ : préfixe du pseudo
diff --git a/doc/it/weechat_plugin_api.it.adoc b/doc/it/weechat_plugin_api.it.adoc
index a3fcab585..f3d001cac 100644
--- a/doc/it/weechat_plugin_api.it.adoc
+++ b/doc/it/weechat_plugin_api.it.adoc
@@ -15398,6 +15398,8 @@ Argomenti:
 // TRANSLATION MISSING
 ** _type_: type of buffer: "formatted" or "free" _(WeeChat ≥ 4.2.0)_
 ** _title_: titolo del buffer
+// TRANSLATION MISSING
+** _nicklist_last_id_assigned_: last unique identifier used in this buffer for a group or nick _(WeeChat ≥ 4.3.0)_
 ** _input_: testo in ingresso
 ** _text_search_input_: input salvato prima della ricerca nel testo
 ** _highlight_words_: elenco di parole da evidenziare
@@ -16620,6 +16622,8 @@ Argomenti:
 * _buffer_: puntatore al buffer
 * _group_: puntatore al gruppo
 * _property_: nome della proprietà:
+// TRANSLATION MISSING
+** _id_: unique identifier _(WeeChat ≥ 4.3.0)_
 ** _name_: nome del gruppo
 ** _color_: colore del gruppo nella lista nick
 
@@ -16826,6 +16830,8 @@ Argomenti:
 * _buffer_: puntatore al buffer
 * _nick_: puntatore al nick
 * _property_: nome della proprietà:
+// TRANSLATION MISSING
+** _id_: unique identifier _(WeeChat ≥ 4.3.0)_
 ** _name_: nome del nick
 ** _color_: colore del nick nella lista nick
 ** _prefix_: prefisso del nick
diff --git a/doc/ja/weechat_dev.ja.adoc b/doc/ja/weechat_dev.ja.adoc
index bbf6791cc..6c054b398 100644
--- a/doc/ja/weechat_dev.ja.adoc
+++ b/doc/ja/weechat_dev.ja.adoc
@@ -508,6 +508,8 @@ WeeChat "core" は以下のディレクトリに配置されています:
 // TRANSLATION MISSING
 |          test-gui-nick.cpp                 | テスト: nicks
 // TRANSLATION MISSING
+|          test-gui-nicklist.cpp             | Tests: nicklist functions.
+// TRANSLATION MISSING
 |          curses/                           | Root of unit tests for Curses interface.
 // TRANSLATION MISSING
 |             test-gui-curses-mouse.cpp      | Tests: mouse (Curses interface).
diff --git a/doc/ja/weechat_plugin_api.ja.adoc b/doc/ja/weechat_plugin_api.ja.adoc
index a38b6fd95..6b8ea1577 100644
--- a/doc/ja/weechat_plugin_api.ja.adoc
+++ b/doc/ja/weechat_plugin_api.ja.adoc
@@ -14933,6 +14933,8 @@ const char *weechat_buffer_get_string (struct t_gui_buffer *buffer,
 // TRANSLATION MISSING
 ** _type_: type of buffer: "formatted" or "free" _(WeeChat ≥ 4.2.0)_
 ** _title_: バッファのタイトル
+// TRANSLATION MISSING
+** _nicklist_last_id_assigned_: last unique identifier used in this buffer for a group or nick _(WeeChat ≥ 4.3.0)_
 ** _input_: 入力テキスト
 ** _text_search_input_: テキスト検索前に保存した入力テキスト
 ** _highlight_words_: ハイライトする単語のリスト
@@ -16112,6 +16114,8 @@ const char *weechat_nicklist_group_get_string (struct t_gui_buffer *buffer,
 * _buffer_: バッファへのポインタ
 * _group_: グループへのポインタ
 * _property_: プロパティ名:
+// TRANSLATION MISSING
+** _id_: unique identifier _(WeeChat ≥ 4.3.0)_
 ** _name_: グループの名前
 ** _color_: ニックネームリストのグループ色
 
@@ -16315,6 +16319,8 @@ const char *weechat_nicklist_nick_get_string (struct t_gui_buffer *buffer,
 * _buffer_: バッファへのプロパティ
 * _nick_: ニックネームへのポインタ
 * _property_: プロパティ名:
+// TRANSLATION MISSING
+** _id_: unique identifier _(WeeChat ≥ 4.3.0)_
 ** _name_: ニックネームの名前
 ** _color_: ニックネームリスト内でのニックネームの色
 ** _prefix_: ニックネームのプレフィックス
diff --git a/doc/sr/weechat_dev.sr.adoc b/doc/sr/weechat_dev.sr.adoc
index 369eb7cdb..fd0df161b 100644
--- a/doc/sr/weechat_dev.sr.adoc
+++ b/doc/sr/weechat_dev.sr.adoc
@@ -456,6 +456,8 @@ WeeChat „језгро” се налази у следећим директо�
 |          test-gui-line.cpp                 | Тестови: линије.
 |          test-gui-nick.cpp                 | Тестови: надимци.
 // TRANSLATION MISSING
+|          test-gui-nicklist.cpp             | Tests: nicklist functions.
+// TRANSLATION MISSING
 |          curses/                           | Root of unit tests for Curses interface.
 // TRANSLATION MISSING
 |             test-gui-curses-mouse.cpp      | Tests: mouse (Curses interface).
diff --git a/doc/sr/weechat_plugin_api.sr.adoc b/doc/sr/weechat_plugin_api.sr.adoc
index 456f478a7..19955a3e2 100644
--- a/doc/sr/weechat_plugin_api.sr.adoc
+++ b/doc/sr/weechat_plugin_api.sr.adoc
@@ -14292,6 +14292,8 @@ const char *weechat_buffer_get_string (struct t_gui_buffer *buffer,
 ** _short_name_: кратко име бафера (напомена: користи се само за приказ и корисник може да га промени, ово не сме да се употребљава за проналажење имена бафера, уместо њега употребите _name_, _full_name_ или локалну променљиву _channel_)
 ** _type_: тип бафера: „formatted” или „free” _(WeeChat ≥ 4.2.0)_
 ** _title_: наслов бафера
+// TRANSLATION MISSING
+** _nicklist_last_id_assigned_: last unique identifier used in this buffer for a group or nick _(WeeChat ≥ 4.3.0)_
 ** _input_: текст уноса
 ** _text_search_input_: сачувани унос пре претраге текста
 ** _highlight_words_: листа речи које се истичу
@@ -15450,6 +15452,8 @@ const char *weechat_nicklist_group_get_string (struct t_gui_buffer *buffer,
 * _buffer_: показивач на бафер
 * _group_: показивач на групу
 * _property_: име особине:
+// TRANSLATION MISSING
+** _id_: unique identifier _(WeeChat ≥ 4.3.0)_
 ** _name_: име групе
 ** _color_: боја групе у листи надимака
 
@@ -15652,6 +15656,8 @@ const char *weechat_nicklist_nick_get_string (struct t_gui_buffer *buffer,
 * _buffer_: показивач на бафер
 * _nick_: показивач на надимак
 * _property_: име особине:
+// TRANSLATION MISSING
+** _id_: unique identifier _(WeeChat ≥ 4.3.0)_
 ** _name_: име надимка
 ** _color_: боја надимка у листи надимака
 ** _prefix_: префикс надимка
diff --git a/src/core/core-upgrade.c b/src/core/core-upgrade.c
index b5c6f2ca7..ed03302dc 100644
--- a/src/core/core-upgrade.c
+++ b/src/core/core-upgrade.c
@@ -711,7 +711,9 @@ void
 upgrade_weechat_read_nicklist (struct t_infolist *infolist)
 {
     struct t_gui_nick_group *ptr_group;
-    const char *type, *name, *group_name;
+    const char *type, *name, *group_name, *ptr_id;
+    char *error;
+    long long id;
 
     if (!upgrade_current_buffer)
         return;
@@ -719,41 +721,62 @@ upgrade_weechat_read_nicklist (struct t_infolist *infolist)
     upgrade_current_buffer->nicklist = 1;
     ptr_group = NULL;
     type = infolist_string (infolist, "type");
-    if (type)
+    if (!type)
+        return;
+
+    /* "id" is new in WeeChat 4.3.0 */
+    id = -1;
+    if (infolist_search_var (infolist, "id"))
     {
-        if (strcmp (type, "group") == 0)
+        ptr_id = infolist_string (infolist, "id");
+        if (ptr_id)
         {
-            name = infolist_string (infolist, "name");
-            if (name && (strcmp (name, "root") != 0))
+            error = NULL;
+            id = strtoll (ptr_id, &error, 10);
+            if (!error || error[0])
+                id = -1;
+        }
+    }
+    if (id < 0)
+        id = gui_nicklist_generate_id (upgrade_current_buffer);
+
+    if (strcmp (type, "group") == 0)
+    {
+        name = infolist_string (infolist, "name");
+        if (name && (strcmp (name, "root") != 0))
+        {
+            group_name = infolist_string (infolist, "parent_name");
+            if (group_name)
             {
-                group_name = infolist_string (infolist, "parent_name");
-                if (group_name)
-                {
-                    ptr_group = gui_nicklist_search_group (
-                        upgrade_current_buffer, NULL, group_name);
-                }
-                gui_nicklist_add_group (upgrade_current_buffer,
-                                        ptr_group,
-                                        name,
-                                        infolist_string (infolist, "color"),
-                                        infolist_integer (infolist, "visible"));
+                ptr_group = gui_nicklist_search_group (
+                    upgrade_current_buffer, NULL, group_name);
             }
+            gui_nicklist_add_group_with_id (
+                upgrade_current_buffer,
+                id,
+                ptr_group,
+                name,
+                infolist_string (infolist, "color"),
+                infolist_integer (infolist, "visible"));
         }
-        else if (strcmp (type, "nick") == 0)
+    }
+    else if (strcmp (type, "nick") == 0)
+    {
+        group_name = infolist_string (infolist, "group_name");
+        if (group_name)
         {
-            group_name = infolist_string (infolist, "group_name");
-            if (group_name)
-                ptr_group = gui_nicklist_search_group (upgrade_current_buffer,
-                                                       NULL,
-                                                       group_name);
-            gui_nicklist_add_nick (upgrade_current_buffer,
-                                   ptr_group,
-                                   infolist_string (infolist, "name"),
-                                   infolist_string (infolist, "color"),
-                                   infolist_string (infolist, "prefix"),
-                                   infolist_string (infolist, "prefix_color"),
-                                   infolist_integer (infolist, "visible"));
+            ptr_group = gui_nicklist_search_group (
+                upgrade_current_buffer, NULL, group_name);
         }
+        gui_nicklist_add_nick_with_id (
+            upgrade_current_buffer,
+            id,
+            ptr_group,
+            infolist_string (infolist, "name"),
+            infolist_string (infolist, "color"),
+            infolist_string (infolist, "prefix"),
+            infolist_string (infolist, "prefix_color"),
+            infolist_integer (infolist, "visible"));
     }
 }
 
diff --git a/src/gui/gui-buffer.c b/src/gui/gui-buffer.c
index 8941affea..d7edf0c90 100644
--- a/src/gui/gui-buffer.c
+++ b/src/gui/gui-buffer.c
@@ -110,9 +110,9 @@ char *gui_buffer_properties_get_integer[] =
 };
 char *gui_buffer_properties_get_string[] =
 { "id", "plugin", "name", "full_name", "old_full_name", "short_name", "title",
-  "input", "text_search_input", "highlight_words", "highlight_disable_regex",
-  "highlight_regex", "highlight_tags_restrict", "highlight_tags",
-  "hotlist_max_level_nicks",
+  "nicklist_last_id_assigned", "input", "text_search_input", "highlight_words",
+  "highlight_disable_regex", "highlight_regex", "highlight_tags_restrict",
+  "highlight_tags", "hotlist_max_level_nicks",
   NULL
 };
 char *gui_buffer_properties_get_pointer[] =
@@ -888,10 +888,11 @@ gui_buffer_new_props_with_id (long long id,
     new_buffer->nicklist_groups_visible_count = 0;
     new_buffer->nicklist_nicks_count = 0;
     new_buffer->nicklist_nicks_visible_count = 0;
+    new_buffer->nicklist_last_id_assigned = -1;
     new_buffer->nickcmp_callback = NULL;
     new_buffer->nickcmp_callback_pointer = NULL;
     new_buffer->nickcmp_callback_data = NULL;
-    gui_nicklist_add_group (new_buffer, NULL, "root", NULL, 0);
+    gui_nicklist_add_group_with_id (new_buffer, 0, NULL, "root", NULL, 0);
 
     /* input */
     new_buffer->input = 1;
@@ -1539,6 +1540,12 @@ gui_buffer_get_string (struct t_gui_buffer *buffer, const char *property)
        return gui_buffer_type_string[buffer->type];
     else if (strcmp (property, "title") == 0)
         return buffer->title;
+    else if (strcmp (property, "nicklist_last_id_assigned") == 0)
+    {
+        snprintf (str_value, sizeof (str_value),
+                  "%lld", buffer->nicklist_last_id_assigned);
+        return str_value;
+    }
     else if (strcmp (property, "input") == 0)
         return buffer->input_buffer;
     else if (strcmp (property, "text_search_input") == 0)
@@ -5188,6 +5195,7 @@ gui_buffer_hdata_buffer_cb (const void *pointer, void *data,
         HDATA_VAR(struct t_gui_buffer, nicklist_groups_visible_count, INTEGER, 0, NULL, NULL);
         HDATA_VAR(struct t_gui_buffer, nicklist_nicks_count, INTEGER, 0, NULL, NULL);
         HDATA_VAR(struct t_gui_buffer, nicklist_nicks_visible_count, INTEGER, 0, NULL, NULL);
+        HDATA_VAR(struct t_gui_buffer, nicklist_last_id_assigned, LONGLONG, 0, NULL, NULL);
         HDATA_VAR(struct t_gui_buffer, nickcmp_callback, POINTER, 0, NULL, NULL);
         HDATA_VAR(struct t_gui_buffer, nickcmp_callback_pointer, POINTER, 0, NULL, NULL);
         HDATA_VAR(struct t_gui_buffer, nickcmp_callback_data, POINTER, 0, NULL, NULL);
@@ -5407,6 +5415,9 @@ gui_buffer_add_to_infolist (struct t_infolist *infolist,
         return 0;
     if (!infolist_new_var_integer (ptr_item, "nicklist_nicks_visible_count", buffer->nicklist_nicks_visible_count))
         return 0;
+    snprintf (str_value, sizeof (str_value), "%lld", buffer->nicklist_last_id_assigned);
+    if (!infolist_new_var_string (ptr_item, "nicklist_last_id_assigned", str_value))
+        return 0;
     if (!infolist_new_var_string (ptr_item, "title", buffer->title))
         return 0;
     if (!infolist_new_var_integer (ptr_item, "input", buffer->input))
@@ -5643,6 +5654,7 @@ gui_buffer_print_log ()
         log_printf ("  nicklist_groups_vis_cnt : %d", ptr_buffer->nicklist_groups_visible_count);
         log_printf ("  nicklist_nicks_count. . : %d", ptr_buffer->nicklist_nicks_count);
         log_printf ("  nicklist_nicks_vis_cnt. : %d", ptr_buffer->nicklist_nicks_visible_count);
+        log_printf ("  nicklist_last_id_assigned: %lld", ptr_buffer->nicklist_last_id_assigned);
         log_printf ("  nickcmp_callback. . . . : %p", ptr_buffer->nickcmp_callback);
         log_printf ("  nickcmp_callback_pointer: %p", ptr_buffer->nickcmp_callback_pointer);
         log_printf ("  nickcmp_callback_data . : %p", ptr_buffer->nickcmp_callback_data);
diff --git a/src/gui/gui-buffer.h b/src/gui/gui-buffer.h
index f3de457b6..09373e9be 100644
--- a/src/gui/gui-buffer.h
+++ b/src/gui/gui-buffer.h
@@ -169,6 +169,7 @@ struct t_gui_buffer
     int nicklist_groups_visible_count; /* number of groups displayed        */
     int nicklist_nicks_count;          /* number of nicks                   */
     int nicklist_nicks_visible_count;  /* number of nicks displayed         */
+    long long nicklist_last_id_assigned; /* last id assigned for a grp/nick */
     int (*nickcmp_callback)(const void *pointer, /* called to compare nicks */
                             void *data,          /* (search in nicklist)    */
                             struct t_gui_buffer *buffer,
diff --git a/src/gui/gui-nicklist.c b/src/gui/gui-nicklist.c
index 535c8c6b8..4d0443887 100644
--- a/src/gui/gui-nicklist.c
+++ b/src/gui/gui-nicklist.c
@@ -252,15 +252,45 @@ gui_nicklist_search_group (struct t_gui_buffer *buffer,
 }
 
 /*
- * Adds a group to nicklist.
+ * Returns a new unique id for a group/nick.
+ *
+ * The id is the current time with microseconds precision.
+ * The same time (including microseconds) can be used only one time, so that
+ * all group/nick ids in a given buffer are guaranteed to be unique.
+ */
+
+long long
+gui_nicklist_generate_id (struct t_gui_buffer *buffer)
+{
+    struct timeval tv;
+    long long id;
+
+    gettimeofday (&tv, NULL);
+
+    id = ((long long)tv.tv_sec * 1000000LL) + (long long)(tv.tv_usec);
+
+    /*
+     * ensure we never use the same id for two groups/nicks in the buffer
+     * and that the returned id is strictly greater than the last assigned one
+     * in the buffer
+     */
+    if (id <= buffer->nicklist_last_id_assigned)
+        id = buffer->nicklist_last_id_assigned + 1;
+
+    return id;
+}
+
+/*
+ * Adds a group to nicklist with identifier (internal use).
  *
  * Returns pointer to new group, NULL if error.
  */
 
 struct t_gui_nick_group *
-gui_nicklist_add_group (struct t_gui_buffer *buffer,
-                        struct t_gui_nick_group *parent_group, const char *name,
-                        const char *color, int visible)
+gui_nicklist_add_group_with_id (struct t_gui_buffer *buffer, long long id,
+                                struct t_gui_nick_group *parent_group,
+                                const char *name, const char *color,
+                                int visible)
 {
     struct t_gui_nick_group *new_group;
 
@@ -271,6 +301,9 @@ gui_nicklist_add_group (struct t_gui_buffer *buffer,
     if (!new_group)
         return NULL;
 
+    new_group->id = id;
+    if (new_group->id > buffer->nicklist_last_id_assigned)
+        buffer->nicklist_last_id_assigned = new_group->id;
     new_group->name = (char *)string_shared_get (name);
     new_group->color = (color) ? (char *)string_shared_get (color) : NULL;
     new_group->visible = visible;
@@ -309,6 +342,29 @@ gui_nicklist_add_group (struct t_gui_buffer *buffer,
 }
 
 /*
+ * Adds a group to nicklist.
+ *
+ * Returns pointer to new group, NULL if error.
+ */
+
+struct t_gui_nick_group *
+gui_nicklist_add_group (struct t_gui_buffer *buffer,
+                        struct t_gui_nick_group *parent_group, const char *name,
+                        const char *color, int visible)
+{
+    if (!buffer)
+        return NULL;
+
+    return gui_nicklist_add_group_with_id (
+        buffer,
+        gui_nicklist_generate_id (buffer),
+        parent_group,
+        name,
+        color,
+        visible);
+}
+
+/*
  * Searches for position of a nick (to keep nicklist sorted).
  */
 
@@ -430,17 +486,17 @@ gui_nicklist_search_nick (struct t_gui_buffer *buffer,
 }
 
 /*
- * Adds a nick to nicklist.
+ * Adds a nick to nicklist with identifier (internal use).
  *
  * Returns pointer to new nick, NULL if error.
  */
 
 struct t_gui_nick *
-gui_nicklist_add_nick (struct t_gui_buffer *buffer,
-                       struct t_gui_nick_group *group,
-                       const char *name, const char *color,
-                       const char *prefix, const char *prefix_color,
-                       int visible)
+gui_nicklist_add_nick_with_id (struct t_gui_buffer *buffer, long long id,
+                               struct t_gui_nick_group *group,
+                               const char *name, const char *color,
+                               const char *prefix, const char *prefix_color,
+                               int visible)
 {
     struct t_gui_nick *new_nick;
 
@@ -451,6 +507,9 @@ gui_nicklist_add_nick (struct t_gui_buffer *buffer,
     if (!new_nick)
         return NULL;
 
+    new_nick->id = id;
+    if (new_nick->id > buffer->nicklist_last_id_assigned)
+        buffer->nicklist_last_id_assigned = new_nick->id;
     new_nick->group = (group) ? group : buffer->nicklist_root;
     new_nick->name = (char *)string_shared_get (name);
     new_nick->color = (color) ? (char *)string_shared_get (color) : NULL;
@@ -479,6 +538,33 @@ gui_nicklist_add_nick (struct t_gui_buffer *buffer,
 }
 
 /*
+ * Adds a nick to nicklist.
+ *
+ * Returns pointer to new nick, NULL if error.
+ */
+
+struct t_gui_nick *
+gui_nicklist_add_nick (struct t_gui_buffer *buffer,
+                       struct t_gui_nick_group *group,
+                       const char *name, const char *color,
+                       const char *prefix, const char *prefix_color,
+                       int visible)
+{
+    if (!buffer)
+        return NULL;
+
+    return gui_nicklist_add_nick_with_id (
+        buffer,
+        gui_nicklist_generate_id (buffer),
+        group,
+        name,
+        color,
+        prefix,
+        prefix_color,
+        visible);
+}
+
+/*
  * Removes a nick from a group.
  */
 
@@ -1078,6 +1164,7 @@ gui_nicklist_hdata_nick_group_cb (const void *pointer, void *data,
                        0, 0, NULL, NULL);
     if (hdata)
     {
+        HDATA_VAR(struct t_gui_nick_group, id, LONGLONG, 0, NULL, NULL);
         HDATA_VAR(struct t_gui_nick_group, name, SHARED_STRING, 0, NULL, NULL);
         HDATA_VAR(struct t_gui_nick_group, color, SHARED_STRING, 0, NULL, NULL);
         HDATA_VAR(struct t_gui_nick_group, visible, INTEGER, 0, NULL, NULL);
@@ -1111,6 +1198,7 @@ gui_nicklist_hdata_nick_cb (const void *pointer, void *data,
                        0, 0, NULL, NULL);
     if (hdata)
     {
+        HDATA_VAR(struct t_gui_nick, id, LONGLONG, 0, NULL, NULL);
         HDATA_VAR(struct t_gui_nick, group, POINTER, 0, NULL, "nick_group");
         HDATA_VAR(struct t_gui_nick, name, SHARED_STRING, 0, NULL, NULL);
         HDATA_VAR(struct t_gui_nick, color, SHARED_STRING, 0, NULL, NULL);
@@ -1136,6 +1224,7 @@ gui_nicklist_add_group_to_infolist (struct t_infolist *infolist,
                                     struct t_gui_nick_group *group)
 {
     struct t_infolist_item *ptr_item;
+    char str_value[64];
 
     if (!infolist || !group)
         return 0;
@@ -1144,6 +1233,9 @@ gui_nicklist_add_group_to_infolist (struct t_infolist *infolist,
     if (!ptr_item)
         return 0;
 
+    snprintf (str_value, sizeof (str_value), "%lld", group->id);
+    if (!infolist_new_var_string (ptr_item, "id", str_value))
+        return 0;
     if (!infolist_new_var_string (ptr_item, "type", "group"))
         return 0;
     if (group->parent)
@@ -1176,6 +1268,7 @@ gui_nicklist_add_nick_to_infolist (struct t_infolist *infolist,
                                    struct t_gui_nick *nick)
 {
     struct t_infolist_item *ptr_item;
+    char str_value[64];
 
     if (!infolist || !nick)
         return 0;
@@ -1184,6 +1277,9 @@ gui_nicklist_add_nick_to_infolist (struct t_infolist *infolist,
     if (!ptr_item)
         return 0;
 
+    snprintf (str_value, sizeof (str_value), "%lld", nick->id);
+    if (!infolist_new_var_string (ptr_item, "id", str_value))
+        return 0;
     if (!infolist_new_var_string (ptr_item, "type", "nick"))
         return 0;
     if (nick->group)
@@ -1274,6 +1370,10 @@ gui_nicklist_print_log (struct t_gui_nick_group *group, int indent)
               (indent * 2) + 4);
     log_printf (format, " ", group);
     snprintf (format, sizeof (format),
+              "%%-%dsid. . . . . : %%lld",
+              (indent * 2) + 6);
+    log_printf (format, " ", group->id);
+    snprintf (format, sizeof (format),
               "%%-%dsname. . . . : '%%s'",
               (indent * 2) + 6);
     log_printf (format, " ", group->name);
@@ -1337,6 +1437,10 @@ gui_nicklist_print_log (struct t_gui_nick_group *group, int indent)
                   (indent * 2) + 6);
         log_printf (format, " ", ptr_nick->group);
         snprintf (format, sizeof (format),
+                  "%%-%dsid. . . . . . . : %%lld",
+                  (indent * 2) + 6);
+        log_printf (format, " ", ptr_nick->id);
+        snprintf (format, sizeof (format),
                   "%%-%dsname. . . . . . : '%%s'",
                   (indent * 2) + 6);
         log_printf (format, " ", ptr_nick->name);
diff --git a/src/gui/gui-nicklist.h b/src/gui/gui-nicklist.h
index 752767e12..ce0d3c7e9 100644
--- a/src/gui/gui-nicklist.h
+++ b/src/gui/gui-nicklist.h
@@ -25,6 +25,7 @@ struct t_infolist;
 
 struct t_gui_nick_group
 {
+    long long id;                      /* unique id for group/nick in buffer*/
     char *name;                        /* group name                        */
     char *color;                       /* color for group in nicklist       */
     int visible;                       /* 1 if group is displayed           */
@@ -40,6 +41,7 @@ struct t_gui_nick_group
 
 struct t_gui_nick
 {
+    long long id;                      /* unique id for group/nick in buffer*/
     struct t_gui_nick_group *group;    /* group which contains nick         */
     char *name;                        /* nick name                         */
     char *color;                       /* color for nick in nicklist        */
@@ -55,6 +57,13 @@ struct t_gui_nick
 extern struct t_gui_nick_group *gui_nicklist_search_group (struct t_gui_buffer *buffer,
                                                            struct t_gui_nick_group *from_group,
                                                            const char *name);
+extern long long gui_nicklist_generate_id (struct t_gui_buffer *buffer);
+extern struct t_gui_nick_group *gui_nicklist_add_group_with_id (struct t_gui_buffer *buffer,
+                                                                long long id,
+                                                                struct t_gui_nick_group *parent_group,
+                                                                const char *name,
+                                                                const char *color,
+                                                                int visible);
 extern struct t_gui_nick_group *gui_nicklist_add_group (struct t_gui_buffer *buffer,
                                                         struct t_gui_nick_group *parent_group,
                                                         const char *name,
@@ -63,6 +72,14 @@ extern struct t_gui_nick_group *gui_nicklist_add_group (struct t_gui_buffer *buf
 extern struct t_gui_nick *gui_nicklist_search_nick (struct t_gui_buffer *buffer,
                                                     struct t_gui_nick_group *from_group,
                                                     const char *name);
+extern struct t_gui_nick *gui_nicklist_add_nick_with_id (struct t_gui_buffer *buffer,
+                                                         long long id,
+                                                         struct t_gui_nick_group *group,
+                                                         const char *name,
+                                                         const char *color,
+                                                         const char *prefix,
+                                                         const char *prefix_color,
+                                                         int visible);
 extern struct t_gui_nick *gui_nicklist_add_nick (struct t_gui_buffer *buffer,
                                                  struct t_gui_nick_group *group,
                                                  const char *name,
diff --git a/src/plugins/irc/irc-channel.c b/src/plugins/irc/irc-channel.c
index 1b45f17df..6382fad1c 100644
--- a/src/plugins/irc/irc-channel.c
+++ b/src/plugins/irc/irc-channel.c
@@ -33,12 +33,13 @@
 #include "irc-color.h"
 #include "irc-command.h"
 #include "irc-config.h"
+#include "irc-input.h"
 #include "irc-join.h"
 #include "irc-modelist.h"
 #include "irc-nick.h"
 #include "irc-protocol.h"
 #include "irc-server.h"
-#include "irc-input.h"
+#include "irc-upgrade.h"
 
 
 char *irc_channel_typing_state_string[IRC_CHANNEL_NUM_TYPING_STATES] =
@@ -241,7 +242,8 @@ irc_channel_create_buffer (struct t_irc_server *server,
 
     if (ptr_buffer)
     {
-        weechat_nicklist_remove_all (ptr_buffer);
+        if (!irc_upgrading)
+            weechat_nicklist_remove_all (ptr_buffer);
         weechat_hashtable_map (buffer_props, &irc_channel_apply_props, ptr_buffer);
     }
     else
diff --git a/src/plugins/irc/irc-nick.c b/src/plugins/irc/irc-nick.c
index f00bbc006..f3ee654d9 100644
--- a/src/plugins/irc/irc-nick.c
+++ b/src/plugins/irc/irc-nick.c
@@ -521,41 +521,25 @@ irc_nick_nicklist_set_color_all ()
 }
 
 /*
- * Adds a new nick in channel.
+ * Adds a new nick in channel, but do not update the buffer nicklist.
+ * This function is only called by the function `irc_nick_new` (below) and
+ * when restoring nicks after upgrade: in this case we want to just add nick
+ * in channel nicks without changing anything in the buffer nicklist,
+ * to preserve same identifiers).
  *
  * Returns pointer to new nick, NULL if error.
  */
 
 struct t_irc_nick *
-irc_nick_new (struct t_irc_server *server, struct t_irc_channel *channel,
-              const char *nickname, const char *host, const char *prefixes,
-              int away, const char *account, const char *realname)
+irc_nick_new_in_channel (struct t_irc_server *server,
+                         struct t_irc_channel *channel,
+                         const char *nickname, const char *host,
+                         const char *prefixes, int away, const char *account,
+                         const char *realname)
 {
-    struct t_irc_nick *new_nick, *ptr_nick;
+    struct t_irc_nick *new_nick;
     int length;
 
-    if (!nickname || !nickname[0])
-        return NULL;
-
-    if (!channel->nicks)
-        irc_channel_add_nicklist_groups (server, channel);
-
-    /* nick already exists on this channel? */
-    ptr_nick = irc_nick_search (server, channel, nickname);
-    if (ptr_nick)
-    {
-        /* remove old nick from nicklist */
-        irc_nick_nicklist_remove (server, channel, ptr_nick);
-
-        /* update nick prefixes */
-        irc_nick_set_prefixes (server, ptr_nick, prefixes);
-
-        /* add new nick in nicklist */
-        irc_nick_nicklist_add (server, channel, ptr_nick);
-
-        return ptr_nick;
-    }
-
     /* alloc memory for new nick */
     if ((new_nick = malloc (sizeof (*new_nick))) == NULL)
         return NULL;
@@ -609,6 +593,49 @@ irc_nick_new (struct t_irc_server *server, struct t_irc_channel *channel,
 
     channel->nick_completion_reset = 1;
 
+    return new_nick;
+}
+
+/*
+ * Adds a new nick in channel.
+ *
+ * Returns pointer to new nick, NULL if error.
+ */
+
+struct t_irc_nick *
+irc_nick_new (struct t_irc_server *server, struct t_irc_channel *channel,
+              const char *nickname, const char *host, const char *prefixes,
+              int away, const char *account, const char *realname)
+{
+    struct t_irc_nick *new_nick, *ptr_nick;
+
+    if (!nickname || !nickname[0])
+        return NULL;
+
+    if (!channel->nicks)
+        irc_channel_add_nicklist_groups (server, channel);
+
+    /* nick already exists on this channel? */
+    ptr_nick = irc_nick_search (server, channel, nickname);
+    if (ptr_nick)
+    {
+        /* remove old nick from nicklist */
+        irc_nick_nicklist_remove (server, channel, ptr_nick);
+
+        /* update nick prefixes */
+        irc_nick_set_prefixes (server, ptr_nick, prefixes);
+
+        /* add new nick in nicklist */
+        irc_nick_nicklist_add (server, channel, ptr_nick);
+
+        return ptr_nick;
+    }
+
+    new_nick = irc_nick_new_in_channel (server, channel, nickname, host,
+                                        prefixes, away, account, realname);
+    if (!new_nick)
+        return NULL;
+
     /* add nick to buffer nicklist */
     irc_nick_nicklist_add (server, channel, new_nick);
 
diff --git a/src/plugins/irc/irc-nick.h b/src/plugins/irc/irc-nick.h
index 4c3d07a9e..3a1cc80e2 100644
--- a/src/plugins/irc/irc-nick.h
+++ b/src/plugins/irc/irc-nick.h
@@ -61,6 +61,14 @@ extern const char *irc_nick_get_prefix_color_name (struct t_irc_server *server,
                                                    char prefix);
 extern void irc_nick_nicklist_set_prefix_color_all ();
 extern void irc_nick_nicklist_set_color_all ();
+extern struct t_irc_nick *irc_nick_new_in_channel (struct t_irc_server *server,
+                                                   struct t_irc_channel *channel,
+                                                   const char *nickname,
+                                                   const char *host,
+                                                   const char *prefixes,
+                                                   int away,
+                                                   const char *account,
+                                                   const char *realname);
 extern struct t_irc_nick *irc_nick_new (struct t_irc_server *server,
                                         struct t_irc_channel *channel,
                                         const char *nickname,
diff --git a/src/plugins/irc/irc-upgrade.c b/src/plugins/irc/irc-upgrade.c
index 402a225e4..4a82af10f 100644
--- a/src/plugins/irc/irc-upgrade.c
+++ b/src/plugins/irc/irc-upgrade.c
@@ -42,6 +42,7 @@
 struct t_irc_server *irc_upgrade_current_server = NULL;
 struct t_irc_channel *irc_upgrade_current_channel = NULL;
 struct t_irc_modelist *irc_upgrade_current_modelist = NULL;
+int irc_upgrading = 0;
 
 
 /*
@@ -795,14 +796,15 @@ irc_upgrade_read_cb (const void *pointer, void *data,
             case IRC_UPGRADE_TYPE_NICK:
                 if (irc_upgrade_current_server && irc_upgrade_current_channel)
                 {
-                    ptr_nick = irc_nick_new (irc_upgrade_current_server,
-                                             irc_upgrade_current_channel,
-                                             weechat_infolist_string (infolist, "name"),
-                                             weechat_infolist_string (infolist, "host"),
-                                             weechat_infolist_string (infolist, "prefixes"),
-                                             weechat_infolist_integer (infolist, "away"),
-                                             weechat_infolist_string (infolist, "account"),
-                                             weechat_infolist_string (infolist, "realname"));
+                    ptr_nick = irc_nick_new_in_channel (
+                        irc_upgrade_current_server,
+                        irc_upgrade_current_channel,
+                        weechat_infolist_string (infolist, "name"),
+                        weechat_infolist_string (infolist, "host"),
+                        weechat_infolist_string (infolist, "prefixes"),
+                        weechat_infolist_integer (infolist, "away"),
+                        weechat_infolist_string (infolist, "account"),
+                        weechat_infolist_string (infolist, "realname"));
                     if (ptr_nick)
                     {
                         /*
@@ -1005,7 +1007,9 @@ irc_upgrade_load ()
     if (!upgrade_file)
         return 0;
 
+    irc_upgrading = 1;
     rc = weechat_upgrade_read (upgrade_file);
+    irc_upgrading = 0;
 
     weechat_upgrade_close (upgrade_file);
 
diff --git a/src/plugins/irc/irc-upgrade.h b/src/plugins/irc/irc-upgrade.h
index c33e44d07..af2008f15 100644
--- a/src/plugins/irc/irc-upgrade.h
+++ b/src/plugins/irc/irc-upgrade.h
@@ -37,6 +37,8 @@ enum t_irc_upgrade_type
     IRC_UPGRADE_TYPE_MODELIST_ITEM,
 };
 
+extern int irc_upgrading;
+
 extern int irc_upgrade_save (int force_disconnected_state);
 extern int irc_upgrade_load ();
 
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index cbce96b30..28e818fbb 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -83,6 +83,7 @@ set(LIB_WEECHAT_UNIT_TESTS_CORE_SRC
   unit/gui/test-gui-key.cpp
   unit/gui/test-gui-line.cpp
   unit/gui/test-gui-nick.cpp
+  unit/gui/test-gui-nicklist.cpp
   unit/gui/curses/test-gui-curses-mouse.cpp
   scripts/test-scripts.cpp
 )
diff --git a/tests/tests.cpp b/tests/tests.cpp
index 93703896a..f0e801323 100644
--- a/tests/tests.cpp
+++ b/tests/tests.cpp
@@ -94,6 +94,7 @@ IMPORT_TEST_GROUP(GuiInput);
 IMPORT_TEST_GROUP(GuiKey);
 IMPORT_TEST_GROUP(GuiLine);
 IMPORT_TEST_GROUP(GuiNick);
+IMPORT_TEST_GROUP(GuiNicklist);
 /* GUI - Curses */
 IMPORT_TEST_GROUP(GuiCursesMouse);
 /* scripts */
diff --git a/tests/unit/gui/test-gui-nicklist.cpp b/tests/unit/gui/test-gui-nicklist.cpp
new file mode 100644
index 000000000..74e523816
--- /dev/null
+++ b/tests/unit/gui/test-gui-nicklist.cpp
@@ -0,0 +1,412 @@
+/*
+ * test-gui-nicklist.cpp - test nicklist functions
+ *
+ * Copyright (C) 2024 Sébastien Helleu <flashcode@flashtux.org>
+ *
+ * This file is part of WeeChat, the extensible chat client.
+ *
+ * WeeChat 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.
+ *
+ * WeeChat 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 WeeChat.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "CppUTest/TestHarness.h"
+
+extern "C"
+{
+#include <string.h>
+#include "src/gui/gui-buffer.h"
+#include "src/gui/gui-nicklist.h"
+}
+
+#define TEST_BUFFER_NAME "test"
+
+TEST_GROUP(GuiNicklist)
+{
+};
+
+/*
+ * Tests functions:
+ *   gui_nicklist_send_signal
+ */
+
+TEST(GuiNicklist, SendSignal)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_send_hsignal
+ */
+
+TEST(GuiNicklist, SendHsignal)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_find_pos_group
+ */
+
+TEST(GuiNicklist, FindPosGroup)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_insert_group_sorted
+ */
+
+TEST(GuiNicklist, InsertGroupSorted)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_search_group_internal
+ */
+
+TEST(GuiNicklist, SearchGroupInternal)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_search_group
+ */
+
+TEST(GuiNicklist, SearchGroup)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_generate_id
+ */
+
+TEST(GuiNicklist, GenerateId)
+{
+    struct t_gui_buffer *buffer;
+    long long id;
+
+    buffer = gui_buffer_new (NULL, TEST_BUFFER_NAME,
+                             NULL, NULL, NULL,
+                             NULL, NULL, NULL);
+    CHECK(buffer);
+
+    CHECK(buffer->nicklist_last_id_assigned == 0);
+
+    id = gui_nicklist_generate_id (buffer);
+    CHECK(id > buffer->nicklist_last_id_assigned);
+    id = gui_buffer_generate_id ();
+    CHECK(id > buffer->nicklist_last_id_assigned);
+    id = gui_buffer_generate_id ();
+    CHECK(id > buffer->nicklist_last_id_assigned);
+
+    gui_buffer_close (buffer);
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_add_group_with_id
+ */
+
+TEST(GuiNicklist, AddGroupWithId)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_add_group
+ */
+
+TEST(GuiNicklist, AddGroup)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_find_pos_nick
+ */
+
+TEST(GuiNicklist, FindPosNick)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_insert_nick_sorted
+ */
+
+TEST(GuiNicklist, InsertNickSorted)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_search_nick
+ */
+
+TEST(GuiNicklist, SearchNick)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_add_nick_with_id
+ */
+
+TEST(GuiNicklist, AddNickWithId)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_add_nick
+ */
+
+TEST(GuiNicklist, AddNick)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_remove_nick
+ */
+
+TEST(GuiNicklist, RemoveNick)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_remove_group
+ */
+
+TEST(GuiNicklist, RemoveGroup)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_remove_all
+ */
+
+TEST(GuiNicklist, RemoveAll)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_get_next_item
+ */
+
+TEST(GuiNicklist, GetNextItem)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_get_group_start
+ */
+
+TEST(GuiNicklist, GetGroupStart)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_get_max_length
+ */
+
+TEST(GuiNicklist, GetMaxLength)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_compute_visible_count
+ */
+
+TEST(GuiNicklist, ComputeVisibleCount)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_group_get_integer
+ */
+
+TEST(GuiNicklist, GroupGetInteger)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_group_get_string
+ */
+
+TEST(GuiNicklist, GroupGetString)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_group_get_pointer
+ */
+
+TEST(GuiNicklist, GroupGetPointer)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_group_set
+ */
+
+TEST(GuiNicklist, GroupSet)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_nick_get_integer
+ */
+
+TEST(GuiNicklist, NickGetInteger)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_nick_get_string
+ */
+
+TEST(GuiNicklist, NickGetString)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_nick_get_pointer
+ */
+
+TEST(GuiNicklist, NickGetPointer)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_nick_set
+ */
+
+TEST(GuiNicklist, NickSet)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_hdata_nick_group_cb
+ */
+
+TEST(GuiNicklist, HdataNickGroupCb)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_hdata_nick_cb
+ */
+
+TEST(GuiNicklist, HdataNickCb)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_add_group_to_infolist
+ */
+
+TEST(GuiNicklist, AddGroupToInfolist)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_add_nick_to_infolist
+ */
+
+TEST(GuiNicklist, AddNickToInfolist)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_add_to_infolist
+ */
+
+TEST(GuiNicklist, AddToInfolist)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_print_log
+ */
+
+TEST(GuiNicklist, PrintLog)
+{
+    /* TODO: write tests */
+}
+
+/*
+ * Tests functions:
+ *   gui_nicklist_end
+ */
+
+TEST(GuiNicklist, End)
+{
+    /* TODO: write tests */
+}