[gnome-shell/gnome-3-38] appDisplay: Do not bind popdown call to grabHelper onUngrab

[Marco Trevisan <marcotrevi src gnome org>]

commit 9a95c8e997498e56352d054b3c648011daa1208f
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Thu Feb 4 16:37:02 2021 +0000

    appDisplay: Do not bind popdown call to grabHelper onUngrab
    
    grabHelper is passing a boolean argument to onUngrab() callback function
    and since commit 1acbdcc9b3b0 we'd end up adding it to to the callback list or
    we'd try to invoke it:
    
     (gnome-shell:3490851): Gjs-CRITICAL **: 17:19:20.460: JS ERROR:
      TypeError: func is not a function
      onComplete/<@/media/M2/GNOME/gnome-shell/js/ui/appDisplay.js:2407:56
      onComplete@/media/M2/GNOME/gnome-shell/js/ui/appDisplay.js:2407:40
      _makeEaseCallback/<@/media/M2/GNOME/gnome-shell/js/ui/environment.js:85:13
      _easeActor/<@/media/M2/GNOME/gnome-shell/js/ui/environment.js:170:64
    
    Use an arrow function so that we can control the parameters we pass
    to popdown.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1635>
    
    
    (cherry picked from commit e641547ddf2c2afb42b4f2d3f250d84e1463a710)

 js/ui/appDisplay.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index 004be086e8..399ab54bd9 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -2489,8 +2489,10 @@ var AppFolderDialog = GObject.registerClass({
         if (this._isOpen)
             return;
 
-        this._isOpen = this._grabHelper.grab({ actor: this,
-                                               onUngrab: this.popdown.bind(this) });
+        this._isOpen = this._grabHelper.grab({
+            actor: this,
+            onUngrab: () => this.popdown(),
+        });
 
         if (!this._isOpen)
             return;