core: send buffer pointer (when possible) in signal "hotlist_changed" (closes #1133)

When a buffer is added or updated in the hotlist, the buffer pointer is sent.
When the hotlist is cleared or resorted, the buffer pointer is NULL.

ChangeLog.adoc

@@ -20,6 +20,7 @@ https://weechat.org/files/releasenotes/ReleaseNotes-devel.html[release notes]
 
 New features::
 
+  * core: send buffer pointer (when possible) in signal "hotlist_changed" (issue #1133)
   * core: add support of list options in curl (issue #826, issue #219)
   * core: allow merge of buffers by name in command /buffer (issue #1108, issue #1159)
   * api: add function hashtable_add_from_infolist()

doc/en/weechat_plugin_api.en.adoc

@@ -9717,7 +9717,7 @@ List of signals sent by WeeChat and plugins:
   Filters disabled.
 
 | weechat | hotlist_changed |
-  - |
+  Pointer: buffer (can be NULL). |
   Hotlist changed.
 
 | weechat | input_paste_pending |

doc/fr/weechat_plugin_api.fr.adoc

@@ -9907,7 +9907,7 @@ Liste des signaux envoyés par WeeChat et les extensions :
   Filtres désactivés.
 
 | weechat | hotlist_changed |
-  - |
+  Pointeur : tampon (peut être NULL). |
   La hotlist a changé.
 
 | weechat | input_paste_pending |

doc/it/weechat_plugin_api.it.adoc

@@ -10080,8 +10080,9 @@ List of signals sent by WeeChat and plugins:
   - |
   Filtri disabilitati.
 
+// TRANSLATION MISSING
 | weechat | hotlist_changed |
-  - |
+  Pointer: buffer (can be NULL). |
   Hotlist modificata.
 
 | weechat | input_paste_pending |

doc/ja/weechat_plugin_api.ja.adoc

@@ -9676,8 +9676,9 @@ WeeChat とプラグインが送信するシグナルのリスト:
   - |
   フィルタを無効化
 
+// TRANSLATION MISSING
 | weechat | hotlist_changed |
-  - |
+  Pointer: バッファ (can be NULL) |
   ホットリストが変更された
 
 | weechat | input_paste_pending |

src/gui/gui-hotlist.c

@@ -59,10 +59,10 @@ int gui_add_hotlist = 1;                    /* 0 is for temporarily disable */
  */
 
 void
-gui_hotlist_changed_signal ()
+gui_hotlist_changed_signal (struct t_gui_buffer *buffer)
 {
     (void) hook_signal_send ("hotlist_changed",
-                             WEECHAT_HOOK_SIGNAL_STRING, NULL);
+                             WEECHAT_HOOK_SIGNAL_POINTER, buffer);
 }
 
 /*
@@ -382,7 +382,7 @@ gui_hotlist_add (struct t_gui_buffer *buffer,
         if (ptr_hotlist->priority >= priority)
         {
             ptr_hotlist->count[priority]++;
-            gui_hotlist_changed_signal ();
+            gui_hotlist_changed_signal (buffer);
             return ptr_hotlist;
         }
 
@@ -415,7 +415,7 @@ gui_hotlist_add (struct t_gui_buffer *buffer,
 
     gui_hotlist_add_hotlist (&gui_hotlist, &last_gui_hotlist, new_hotlist);
 
-    gui_hotlist_changed_signal ();
+    gui_hotlist_changed_signal (buffer);
 
     return new_hotlist;
 }
@@ -471,7 +471,7 @@ gui_hotlist_resort ()
     gui_hotlist = new_hotlist;
     last_gui_hotlist = last_new_hotlist;
 
-    gui_hotlist_changed_signal ();
+    gui_hotlist_changed_signal (NULL);
 }
 
 /*
@@ -510,7 +510,7 @@ gui_hotlist_clear (int level_mask)
     }
 
     if (hotlist_changed)
-        gui_hotlist_changed_signal ();
+        gui_hotlist_changed_signal (NULL);
 }
 
 /*
@@ -562,7 +562,7 @@ gui_hotlist_remove_buffer (struct t_gui_buffer *buffer,
     }
 
     if (hotlist_changed)
-        gui_hotlist_changed_signal ();
+        gui_hotlist_changed_signal (NULL);
 }
 
 /*