Make execCommand("insertImage", false, "") not add a src attribute

Source/core/editing/EditorCommand.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Igalia S.L.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 499 matching lines @@
 static bool executeInsertHTML(LocalFrame& frame, Event*, EditorCommandSource, const String& value)
 {
     ASSERT(frame.document());
     return executeInsertFragment(frame, createFragmentFromMarkup(*frame.document(), value, ""));
 }
 
 static bool executeInsertImage(LocalFrame& frame, Event*, EditorCommandSource, const String& value)
 {
     ASSERT(frame.document());
     RefPtrWillBeRawPtr<HTMLImageElement> image = HTMLImageElement::create(*frame.document());
-    image->setSrc(value);
+    if (!value.isEmpty())
+        image->setSrc(value);
     return executeInsertElement(frame, image.release());
 }
 
 static bool executeInsertLineBreak(LocalFrame& frame, Event* event, EditorCommandSource source, const String&)
 {
     switch (source) {
     case CommandFromMenuOrKeyBinding:
         return targetFrame(frame, event)->eventHandler().handleTextInputEvent("\n", event, TextEventInputLineBreak);
     case CommandFromDOM:
         // Doesn't scroll to make the selection visible, or modify the kill ring.
@@ skipping 1254 matching lines @@
 {
     return m_command && m_command->isTextInsertion;
 }
 
 int Editor::Command::idForHistogram() const
 {
     return isSupported() ? m_command->idForUserMetrics : 0;
 }
 
 } // namespace blink