Event: Don't crash if an element is removed on blur

In Chrome, if an element having a `focusout` handler is blurred by
clicking outside of it, it invokes the handler synchronously. If
that handler calls `.remove()` on the element, the data is cleared,
leaving private data undefined. We're reading a property from that
data so we need to guard against this.

Fixes gh-4417
Closes gh-4799

1 files changed, 7 insertions, 1 deletions

diff --git a/src/event.js b/src/event.js
index b8c5e96fe..4418fbbbf 100644
--- a/src/event.js
+++ b/src/event.js
@@ -558,7 +558,13 @@ function leverageNative( el, type, expectSync ) {
 						// Cancel the outer synthetic event
 						event.stopImmediatePropagation();
 						event.preventDefault();
-						return result.value;
+
+						// Support: Chrome 86+
+						// In Chrome, if an element having a focusout handler is blurred by
+						// clicking outside of it, it invokes the handler synchronously. If
+						// that handler calls `.remove()` on the element, the data is cleared,
+						// leaving `result` undefined. We need to guard against this.
+						return result && result.value;
 					}
 
 				// If this is an inner synthetic event for an event with a bubbling surrogate