From 006d206f98696035770e72ceec712c456122f330 Mon Sep 17 00:00:00 2001
From: Lee <lclark125@gmail.com>
Date: Sat, 24 Apr 2021 18:03:35 +0100
Subject: [PATCH] Magnifier: Filter caret tracking in gnome magnifier

Add a check to filter out caret tracking events that result in a caret
location of 0,0.

Fixes #4177

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1823>
---
 js/ui/magnifier.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/js/ui/magnifier.js b/js/ui/magnifier.js
index 2f0a279a2..08466b9a0 100644
--- a/js/ui/magnifier.js
+++ b/js/ui/magnifier.js
@@ -827,6 +827,12 @@ var ZoomRegion = class ZoomRegion {
         let scaleFactor = St.ThemeContext.get_for_stage(global.stage).scale_factor;
         let [xCaret, yCaret] = [extents.x * scaleFactor, extents.y * scaleFactor];
 
+        // Ignore event(s) if the caret size is none (0x0). This happens a lot if
+        // the cursor offset can't be translated into a location. This is a work
+        // around.
+        if (extents.width === 0 && extents.height === 0)
+            return;
+
         if (this._xCaret !== xCaret || this._yCaret !== yCaret) {
             [this._xCaret, this._yCaret] = [xCaret, yCaret];
             this._centerFromCaretPosition();