[gnome-shell/wip/rstrode/rhel-7.9: 49/86] ibusManager: Work around annotation shortcoming

[Ray Strode <halfline src gnome org>]

commit d9d4e275aa5771353294123d14ddbb41ac8ced8f
Author: Florian Müllner <fmuellner gnome org>
Date:   Mon Jun 22 18:37:14 2020 +0200

    ibusManager: Work around annotation shortcoming
    
    The callback parameter isn't marked as optional, so make sure to
    always pass a callback (even if it ends up not doing anything).

 js/misc/ibusManager.js | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/js/misc/ibusManager.js b/js/misc/ibusManager.js
index 6452e492ff..deb20fee52 100644
--- a/js/misc/ibusManager.js
+++ b/js/misc/ibusManager.js
@@ -204,8 +204,11 @@ var IBusManager = new Lang.Class({
             return;
         }
 
-        this._ibus.set_global_engine_async(id, this._MAX_INPUT_SOURCE_ACTIVATION_TIME,
-                                           null, callback);
+        this._ibus.set_global_engine_async(id,
+            this._MAX_INPUT_SOURCE_ACTIVATION_TIME, null, () => {
+                if (callback)
+                    callback();
+            });
     },
 
     preloadEngines(ids) {