core: fix crash on /buffer close core.weechat

ChangeLog

@@ -11,6 +11,7 @@ http://weechat.org/files/releasenotes/ReleaseNotes-devel.html[release notes]
 
 == Version 0.4.3 (under dev)
 
+* core: fix crash on /buffer close core.weechat
 * core: add option "libs" for command /debug
 * core: apply color attributes when clearing a window (patch #8236)
 * core: set option weechat.look.paste_bracketed to "on" by default

src/core/wee-command.c

@@ -837,7 +837,14 @@ COMMAND_CALLBACK(buffer)
             else
             {
                 ptr_buffer = gui_buffer_search_by_full_name (argv_eol[2]);
-                if (ptr_buffer)
+                if (ptr_buffer == weechat_buffer)
+                {
+                    gui_chat_printf (NULL,
+                                     _("%sError: WeeChat main buffer can't be "
+                                       "closed"),
+                                     gui_chat_prefix[GUI_CHAT_PREFIX_ERROR]);
+                }
+                else
                     gui_buffer_close (ptr_buffer);
             }
         }