[gnome-shell] workspaceThumbnails: Don't animate thumbnail additions while hidden

[Marge Bot <marge-bot src gnome org>]

commit a2751a1b2648946d7046d076047ab6dad3c55d69
Author: Florian Müllner <fmuellner gnome org>
Date:   Tue Feb 16 22:33:28 2021 +0100

    workspaceThumbnails: Don't animate thumbnail additions while hidden
    
    This is not just an obvious mini-optimization, it also ensures that we
    don't start showing the minimap with an ongoing thumbnail transition.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/3739
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1696>

 js/ui/workspaceThumbnail.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/js/ui/workspaceThumbnail.js b/js/ui/workspaceThumbnail.js
index e84764842a..b06e60209a 100644
--- a/js/ui/workspaceThumbnail.js
+++ b/js/ui/workspaceThumbnail.js
@@ -1040,7 +1040,7 @@ var ThumbnailsBox = GObject.registerClass({
             this._thumbnails.push(thumbnail);
             this.add_actor(thumbnail);
 
-            if (start > 0 && this._spliceIndex == -1) {
+            if (this._shouldShow && start > 0 && this._spliceIndex === -1) {
                 // not the initial fill, and not splicing via DND
                 thumbnail.state = ThumbnailState.NEW;
                 thumbnail.slide_position = 1; // start slid out