--- a/src/3rdparty/webkit/WebCore/html/HTMLFormElement.cpp	Fri Apr 16 15:50:13 2010 +0300
+++ b/src/3rdparty/webkit/WebCore/html/HTMLFormElement.cpp	Mon May 03 13:17:34 2010 +0300
@@ -515,11 +515,13 @@
 
 void HTMLFormElement::registerImgElement(HTMLImageElement* e)
 {
+    ASSERT(imgElements.find(e) == notFound);
     imgElements.append(e);
 }
 
 void HTMLFormElement::removeImgElement(HTMLImageElement* e)
 {
+    ASSERT(imgElements.find(e) != notFound);
     removeFromVector(imgElements, e);
 }