relay: fix crash on /upgrade received from a client (weechat protocol)

Some commands like /upgrade sent by relay client can cause problems, because
they were executed immediately (while relay code is running). The /upgrade
command unloads all plugins, so the result is unpredictable (it can cause a
crash).

This commit adds a timer (1 millisecond) to delay the execution of command
after we go back in the WeeChat main loop.

ChangeLog.asciidoc

@@ -62,6 +62,7 @@ http://weechat.org/files/releasenotes/ReleaseNotes-devel.html[release notes]
 * lua: fix interpreter used after unload of a script
 * perl: fix context used after unload of a script
 * python: fix interpreter used after unload of a script
+* relay: fix crash on /upgrade received from a client (weechat protocol)
 * relay: add info "relay_client_count" with optional status name as argument
 * relay: add signals "relay_client_xxx" for client status changes (closes #2)
 * relay: add option relay.network.clients_purge_delay

src/plugins/relay/weechat/relay-weechat-protocol.c

@@ -332,6 +332,43 @@ RELAY_WEECHAT_PROTOCOL_CALLBACK(nicklist)
     return WEECHAT_RC_OK;
 }
 
+/*
+ * Timer callback for input command.
+ */
+
+int
+relay_weechat_protocol_input_timer_cb (void *data,
+                                       int remaining_calls)
+{
+    char **timer_args;
+    int i;
+    struct t_gui_buffer *ptr_buffer;
+
+    /* make C compiler happy */
+    (void) remaining_calls;
+
+    timer_args = (char **)data;
+
+    if (!timer_args)
+        return WEECHAT_RC_ERROR;
+
+    if (timer_args[0] && timer_args[1] && timer_args[2])
+    {
+        ptr_buffer = weechat_buffer_search (timer_args[0], timer_args[1]);
+        if (ptr_buffer)
+            weechat_command (ptr_buffer, timer_args[2]);
+    }
+
+    for (i = 0; i < 3; i++)
+    {
+        if (timer_args[i])
+            free (timer_args[i]);
+    }
+    free (timer_args);
+
+    return WEECHAT_RC_OK;
+}
+
 /*
  * Callback for command "input" (from client).
  *
@@ -344,7 +381,7 @@ RELAY_WEECHAT_PROTOCOL_CALLBACK(nicklist)
 RELAY_WEECHAT_PROTOCOL_CALLBACK(input)
 {
     struct t_gui_buffer *ptr_buffer;
-    char *pos;
+    char *pos, **timer_args;
 
     RELAY_WEECHAT_PROTOCOL_MIN_ARGS(2);
 
@@ -353,7 +390,25 @@ RELAY_WEECHAT_PROTOCOL_CALLBACK(input)
     {
         pos = strchr (argv_eol[0], ' ');
         if (pos)
-            weechat_command (ptr_buffer, pos + 1);
+        {
+            /*
+             * use a timer to execute the command after we go back in the
+             * WeeChat main loop (some commands like /upgrade executed now can
+             * cause a crash)
+             */
+            timer_args = malloc (3 * sizeof (*timer_args));
+            if (timer_args)
+            {
+                timer_args[0] = strdup (weechat_buffer_get_string (ptr_buffer,
+                                                                   "plugin"));
+                timer_args[1] = strdup (weechat_buffer_get_string (ptr_buffer,
+                                                                   "name"));
+                timer_args[2] = strdup (pos + 1);
+                weechat_hook_timer (1, 0, 1,
+                                    &relay_weechat_protocol_input_timer_cb,
+                                    timer_args);
+            }
+        }
     }
 
     return WEECHAT_RC_OK;