From 484a9551d1c14118f9ab66a39a3a7181dbbac1d3 Mon Sep 17 00:00:00 2001
From: Pierre Ossman <ossman@cendio.se>
Date: Thu, 25 Jun 2020 14:37:21 +0200
Subject: [PATCH] Handle quick Cursor detach after mouse up

This timer might fire after the Cursor object has detached from a DOM
element, causing crashes. This will likely not happen in real scenarios,
but the tests are quick enough to trigger this.
---
 core/util/cursor.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/core/util/cursor.js b/core/util/cursor.js
index 009bd6de..4db1dab2 100644
--- a/core/util/cursor.js
+++ b/core/util/cursor.js
@@ -179,6 +179,10 @@ export default class Cursor {
         // should be visible.
         if (this._captureIsActive()) {
             window.setTimeout(() => {
+                // We might have detached at this point
+                if (!this._target) {
+                    return;
+                }
                 // Refresh the target from elementFromPoint since queued events
                 // might have altered the DOM
                 target = document.elementFromPoint(event.clientX,