Make replacing selection in heading/paragraph with heading/paragraph to work

Source/core/editing/ReplaceSelectionCommand.cpp

Index: Source/core/editing/ReplaceSelectionCommand.cpp
diff --git a/Source/core/editing/ReplaceSelectionCommand.cpp b/Source/core/editing/ReplaceSelectionCommand.cpp
index 5552606ea490aa14e0dd73881ecdb3b2caa03785..6bf390d31e15950e63dfd370a0bcdfeca493367f 100644
--- a/Source/core/editing/ReplaceSelectionCommand.cpp
+++ b/Source/core/editing/ReplaceSelectionCommand.cpp
@@ -638,6 +638,9 @@ void ReplaceSelectionCommand::moveNodeOutOfAncestor(PassRefPtr<Node> prpNode, Pa
     RefPtr<Node> node = prpNode;
     RefPtr<Node> ancestor = prpAncestor;
 
+    if (!ancestor->parentNode()->rendererIsEditable())
+        return;
+
     VisiblePosition positionAtEndOfNode = lastPositionInOrAfterNode(node.get());
     VisiblePosition lastPositionInParagraph = lastPositionInNode(ancestor.get());
     if (positionAtEndOfNode == lastPositionInParagraph) {