[BUGFIX] Access parent element in Element Browser correctly

When the element browser is opened in a popup window, the parent element
(=popup) is now accessed properly.

This patch also fixes the case for `list_frame` which didn't work in
Firefox.

Resolves: #83693
Releases: master
Change-Id: I2436942a239b868cd1e3e269c6161a9df92e05ff
Reviewed-on: https://review.typo3.org/55511


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Tested-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>

typo3/sysext/recordlist/Resources/Public/JavaScript/ElementBrowser.js

@@ -87,23 +87,27 @@ define([
 		if (
 			typeof window.parent !== 'undefined' &&
 			typeof window.parent.document.list_frame !== 'undefined' &&
-			window.parent.document.activeElement.classList.contains('t3js-modal-iframe')
+			window.parent.document.list_frame.parent.document.querySelector('.t3js-modal-iframe') !== null
 		) {
 			opener = window.parent.document.list_frame;
-		}
-		else if (
+		} else if (
+			typeof window.parent !== 'undefined' &&
+			typeof window.parent.frames.list_frame !== 'undefined' &&
+			window.parent.frames.list_frame.parent.document.querySelector('.t3js-modal-iframe') !== null
+		) {
+			opener = window.parent.frames.list_frame;
+		} else if (
 			typeof window.frames !== 'undefined' &&
 			typeof window.frames.frameElement !== 'undefined' &&
 			window.frames.frameElement !== null &&
 			window.frames.frameElement.classList.contains('t3js-modal-iframe')
 		) {
-			opener = window.frames.parent.frames.list_frame;
-		}
-		else if (window.opener) {
-			opener = window.opener
+			opener = window.frames.frameElement.contentWindow.parent;
+		} else if (window.opener) {
+			opener = window.opener;
 		}
 		return opener;
-	}
+	};
 
 	/**
 	 *