[gnome-shell/abderrahim/1598-redux] workspacesView: Fix off-by-one error

[Abderrahim Kitouni <akitouni src gnome org>]

commit 1353374e05b2e938c951d542791fdd1fc4272359
Author: Abderrahim Kitouni <akitouni gnome org>
Date:   Tue Feb 9 10:17:29 2021 +0100

    workspacesView: Fix off-by-one error
    
    This is basically 9f0e7632a6 ported over ed1170906b which was dropped this
    fix when copying things around.

 js/ui/workspacesView.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/js/ui/workspacesView.js b/js/ui/workspacesView.js
index 56b5e55eda..9ac7b6a657 100644
--- a/js/ui/workspacesView.js
+++ b/js/ui/workspacesView.js
@@ -167,7 +167,7 @@ class WorkspacesView extends WorkspacesViewBase {
         const rtl = this.text_direction === Clutter.TextDirection.RTL;
         const adj = this._scrollAdjustment;
         const currentWorkspace = vertical || !rtl
-            ? adj.value : adj.upper - adj.value;
+            ? adj.value : adj.upper - adj.value - 1;
 
         // Single fit mode implies centered too
         let x1 = 0;