Index: wp-includes/js/tinymce/tinymce.js
===================================================================
--- wp-includes/js/tinymce/tinymce.js	(revision 31141)
+++ wp-includes/js/tinymce/tinymce.js	(working copy)
@@ -16784,7 +16784,7 @@
 					}
 
 					// Update range positions since they might have changed after the split operations
-					rng.startContainer = startContainer.parentNode;
+					rng.startContainer = startContainer.parentNode ? startContainer.parentNode : startContainer;
 					rng.startOffset = nodeIndex(startContainer);
 					rng.endContainer = endContainer.parentNode;
 					rng.endOffset = nodeIndex(endContainer) + 1;