Selector: Only attach the unload handler in IE & Edge Legacy

mgol · mgol · commit 88d092a2ec32 · 2023-06-29T23:55:04.000+02:00
Both IE & Edge Legacy need the workaround of calling `setDocument()` in an `unload` handler to avoid "permission denied" errors. However, due to not being possible to feature-detect this issue, the handler has been applied in all browsers for windows different than the one in which jQuery was loaded. jQuery 4.0, which drops Edge Legacy support, guards this workaround with a `document.documentMode` check. This won't work in the 3.x line due to still supporting Edge Legacy but we can check for `document.documentElement.msMatchesSelector` instead as that API is supported in IE 9+ and all Edge Legacy versions. Fixes jquerygh-5281 Ref jquerygh-4792
diff --git a/src/selector.js b/src/selector.js
@@ -523,12 +523,17 @@ function setDocument( node ) {
 		documentElement.msMatchesSelector;
 
 	// Support: IE 9 - 11+, Edge 12 - 18+
-	// Accessing iframe documents after unload throws "permission denied" errors (see trac-13936)
-	// Support: IE 11+, Edge 17 - 18+
-	// IE/Edge sometimes throw a "Permission denied" error when strict-comparing
-	// two documents; shallow comparisons work.
-	// eslint-disable-next-line eqeqeq
-	if ( preferredDoc != document &&
+	// Accessing iframe documents after unload throws "permission denied" errors
+	// (see trac-13936).
+	// Limit the fix to IE & Edge Legacy; despite Edge 15+ implementing `matches`,
+	// all IE 9+ and Edge Legacy versions implement `msMatchesSelector` as well.
+	if ( documentElement.msMatchesSelector &&
+
+		// Support: IE 11+, Edge 17 - 18+
+		// IE/Edge sometimes throw a "Permission denied" error when strict-comparing
+		// two documents; shallow comparisons work.
+		// eslint-disable-next-line eqeqeq
+		preferredDoc != document &&
 		( subWindow = document.defaultView ) && subWindow.top !== subWindow ) {
 
 		// Support: IE 9 - 11+, Edge 12 - 18+
