Don't move uneditable paragraph contents in CompositeEditCommand::moveParagraphContentsToNewBlockIfN

Source/core/editing/CompositeEditCommand.cpp

 /*
  * Copyright (C) 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 884 matching lines @@
 
 // If the paragraph is not entirely within it's own block, create one and move the paragraph into
 // it, and return that block.  Otherwise return 0.
 PassRefPtrWillBeRawPtr<Element> CompositeEditCommand::moveParagraphContentsToNewBlockIfNecessary(const Position& pos)
 {
     if (pos.isNull())
         return nullptr;
 
     document().updateLayoutIgnorePendingStylesheets();
 
+    if (!isEditablePosition(pos, ContentIsEditable, DoNotUpdateStyle))

[Yuta Kitamura, 2014/06/13 07:29:01]

I'm not 100% certain whether this check should live here.

This check may perhaps be caller's responsibility, i.e.
each command should check this condition before calling
moveParagraphContentsToNewBlockIfNecessary(), and this
function just ASSERTs that this precondition is met.

WDYT?

[yosin_UTC9, 2014/06/13 09:01:27]

Agree. It should be caller's responsibility.

+        return nullptr;
+
     // It's strange that this function is responsible for verifying that pos has not been invalidated
     // by an earlier call to this function.  The caller, applyBlockStyle, should do this.
     VisiblePosition visiblePos(pos, VP_DEFAULT_AFFINITY);
     VisiblePosition visibleParagraphStart(startOfParagraph(visiblePos));
     VisiblePosition visibleParagraphEnd = endOfParagraph(visiblePos);
     VisiblePosition next = visibleParagraphEnd.next();
     VisiblePosition visibleEnd = next.isNotNull() ? next : visibleParagraphEnd;
 
     Position upstreamStart = visibleParagraphStart.deepEquivalent().upstream();
     Position upstreamEnd = visibleEnd.deepEquivalent().upstream();
@@ skipping 582 matching lines @@
 }
 
 void CompositeEditCommand::trace(Visitor* visitor)
 {
     visitor->trace(m_commands);
     visitor->trace(m_composition);
     EditCommand::trace(visitor);
 }
 
 } // namespace WebCore