ASSERTION FAILED: !style->propertyIsImportant(propertyID) in WebCore::setTextDecorationProperty

Source/core/editing/ApplyStyleCommand.cpp

 /*
  * Copyright (C) 2005, 2006, 2008, 2009 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 980 matching lines @@
 
     return result;
 }
 
 void ApplyStyleCommand::applyInlineStyleToPushDown(Node* node, EditingStyle* style)
 {
     ASSERT(node);
 
     node->document().updateStyleIfNeeded();
 
-    if (!style || style->isEmpty() || !node->renderer())
+    if (!style || style->isEmpty() || !node->renderer() || node->hasTagName(iframeTag))
         return;
 
     RefPtr<EditingStyle> newInlineStyle = style;
     if (node->isHTMLElement() && toHTMLElement(node)->inlineStyle()) {
         newInlineStyle = style->copy();
         newInlineStyle->mergeInlineStyleOfElement(toHTMLElement(node), EditingStyle::OverrideValues);
     }
 
     // Since addInlineStyleIfNeeded can't add styles to block-flow render objects, add style attribute instead.
     // FIXME: applyInlineStyleToRange should be used here instead.
@@ skipping 531 matching lines @@
         String textToMove = nextText->data();
         insertTextIntoNode(childText, childText->length(), textToMove);
         removeNode(next);
         // don't move child node pointer. it may want to merge with more text nodes.
     }
 
     updateStartEnd(newStart, newEnd);
 }
 
 }