[gnome-shell/gbsneto/icon-grid-dnd: 5/10] folderView: Make sure to only add icons once

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 60503639e25490c781edaab6b0d24032aae969a8
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Fri Jul 5 11:36:53 2019 -0300

    folderView: Make sure to only add icons once
    
    FolderView implementation currently allows for adding the same
    icon multiple times.
    
    Ensure the icon is not already added before adding it.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/603

 js/ui/appDisplay.js | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index e4bfa5c45..fb5d8794d 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -1424,6 +1424,9 @@ var FolderView = class FolderView extends BaseAppView {
             if (!app.get_app_info().should_show())
                 return;
 
+            if (apps.some(appIcon => appIcon.id == appId))
+                return;
+
             let icon = new AppIcon(app, this, { hideWhileDragging: true });
             apps.push(icon);
         };