Fix a crash when getElementsByClassName() is called twice with the same argument including capital …

third_party/WebKit/Source/core/dom/ElementTest.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/dom/Element.h"
 
 #include <memory>
 #include "core/dom/ClientRect.h"
 #include "core/dom/Document.h"
 #include "core/editing/EditingTestBase.h"
@@ skipping 221 matching lines @@
   document.View()->UpdateAllLifecyclePhases();
   EXPECT_EQ(DocumentLifecycle::kPaintClean, document.Lifecycle().GetState());
 
   EXPECT_FALSE(outer_sticky->StyleRef().SubtreeIsSticky());
   EXPECT_FALSE(child->StyleRef().SubtreeIsSticky());
   EXPECT_FALSE(grandchild->StyleRef().SubtreeIsSticky());
   EXPECT_TRUE(inner_sticky->StyleRef().SubtreeIsSticky());
   EXPECT_TRUE(great_grandchild->StyleRef().SubtreeIsSticky());
 }
 
+TEST_F(ElementTest, GetElementsByClassNameCrash) {
+  // Test for a crash in NodeListsNodeData::AddCache().
+  ASSERT_TRUE(GetDocument().InQuirksMode());
+  GetDocument().body()->getElementsByClassName("ABC DEF");
+  GetDocument().body()->getElementsByClassName("ABC DEF");
+  // The test passes if no crash happens.
+}
+
 }  // namespace blink