Optimization in handleStyleSpans() for restricting the for loop to iterate only

Source/core/editing/ReplaceSelectionCommand.cpp

 /*
  * Copyright (C) 2005, 2006, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009, 2010, 2011 Google 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
@@ skipping 736 matching lines @@
 // styles are redundant.
 // We should remove the Apple-style-span class when we're done, see <rdar://problem/5685600>.
 // We should remove styles from spans that are overridden by all of their children, either here
 // or at copy time.
 void ReplaceSelectionCommand::handleStyleSpans(InsertedNodes& insertedNodes)
 {
     HTMLElement* wrappingStyleSpan = 0;
     // The style span that contains the source document's default style should be at
     // the top of the fragment, but Mail sometimes adds a wrapper (for Paste As Quotation),
     // so search for the top level style span instead of assuming it's at the top.
-    for (Node* node = insertedNodes.firstNodeInserted(); node; node = NodeTraversal::next(*node)) {
+    Node* pastEndNode = insertedNodes.pastLastLeaf();
+    for (Node* node = insertedNodes.firstNodeInserted(); node && node != pastEndNode; node = NodeTraversal::next(*node)) {
         if (isLegacyAppleStyleSpan(node)) {
             wrappingStyleSpan = toHTMLElement(node);
             break;
         }
     }
 
     // There might not be any style spans if we're pasting from another application or if
     // we are here because of a document.execCommand("InsertHTML", ...) call.
     if (!wrappingStyleSpan)
         return;
@@ skipping 724 matching lines @@
         removeNodeAndPruneAncestors(nodeAfterInsertionPos.get());
 
     VisibleSelection selectionAfterReplace(m_selectReplacement ? start : end, end);
 
     setEndingSelection(selectionAfterReplace);
 
     return true;
 }
 
 } // namespace WebCore