TinyMCE: fix creating a preview when pasting an embeddable URL in Firefox.

Part prop iseulde. Fixes #31988.

git-svn-id: https://develop.svn.wordpress.org/trunk@32229 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/js/tinymce/plugins/wpview/plugin.js

@@ -193,7 +193,7 @@ tinymce.PluginManager.add( 'wpview', function( editor ) {
 				// When a url is pasted or inserted, only try to embed it when it is in an empty paragrapgh.
 				node = editor.dom.getParent( node, 'p' );
 
-				if ( node && /^[\s\uFEFF\u00A0]*$/.test( node.textContent || node.innerText ) ) {
+				if ( node && /^[\s\uFEFF\u00A0]*$/.test( $( node ).text() || '' ) ) {
 					// Make sure there are no empty inline elements in the <p>
 					node.innerHTML = '';
 				} else {