MQParser memory leak fix

Source/core/css/CSSParserValues.cpp

 /*
  * Copyright (C) 2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2008 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 11 matching lines @@
 #include "core/css/CSSParserValues.h"
 
 #include "core/css/CSSFunctionValue.h"
 #include "core/css/CSSSelectorList.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 
 namespace WebCore {
 
 using namespace WTF;
 
+static void destroy(Vector<CSSParserValue, 4>& values)
+{
+    size_t numValues = values.size();
+    for (size_t i = 0; i < numValues; i++) {
+        if (values[i].unit == CSSParserValue::Function)
+            delete values[i].function;
+        else if (values[i].unit == CSSParserValue::ValueList)
+            delete values[i].valueList;
+    }
+}
+
+void CSSParserValueList::destroyAndClear()
+{
+    destroy(m_values);
+    clear();
+}
+
 CSSParserValueList::~CSSParserValueList()
 {
-    size_t numValues = m_values.size();
-    for (size_t i = 0; i < numValues; i++) {
-        if (m_values[i].unit == CSSParserValue::Function)
-            delete m_values[i].function;
-        else if (m_values[i].unit == CSSParserValue::ValueList)
-            delete m_values[i].valueList;
-    }
+    destroy(m_values);

[eseidel, 2014/05/07 15:26:10]

Seems like this could end up destroying twice.  I guess the logic is that
destory i never called w/o clear except here?

Why don't we use a wrapper for CSSParserValue which knows how to destory itself?
 Or perhaps we should just give CSSParserValue a working destructor?

[Yoav Weiss, 2014/05/07 15:34:43]

Yeah, and calling destroyAndClear immediately followed by the destructor does
not damage, since m_values would be empty.
We probably could do that, but since CSSParserValueList has several clients, not
just my code, I'd need to further study what would be the implications of that.

 }
 
 void CSSParserValueList::addValue(const CSSParserValue& v)
 {
     m_values.append(v);
 }
 
 void CSSParserValueList::insertValueAt(unsigned i, const CSSParserValue& v)
 {
     m_values.insert(i, v);
@@ skipping 169 matching lines @@
 {
     CSSParserSelector* selector = const_cast<CSSParserSelector*>(this);
     do {
         if (selector->pseudoType() == CSSSelector::PseudoHost || selector->pseudoType() == CSSSelector::PseudoHostContext)
             return true;
     } while ((selector = selector->tagHistory()));
     return false;
 }
 
 } // namespace WebCore