FULL PRODUCT VERSION :


A DESCRIPTION OF THE PROBLEM :
This is a follow up for my original report - Review ID: JI-9041436.

In July 2013 a new version of webkit was merged into Java FX code base.

The older version of JSValueMakeString wouldn't make a copy:

http://hg.openjdk.java.net/openjfx/8u-dev/rt/file/bcd662ba5826/modules/web/src/main/native/Source/JavaScriptCore/API/OpaqueJSString.cpp
UString OpaqueJSString::ustring() const
{
    if (this && m_characters)
        return UString(m_characters, m_length);
    return UString();
}

http://hg.openjdk.java.net/openjfx/8u-dev/rt/file/bcd662ba5826/modules/web/src/main/native/Source/JavaScriptCore/API/JSValueRef.cpp
JSValueRef JSValueMakeString(JSContextRef ctx, JSStringRef string)
{
    ExecState* exec = toJS(ctx);
    APIEntryShim entryShim(exec);

    return toRef(exec, jsString(exec, string->ustring()));
}

But the new version of OpaqueJSString makes a copy:

http://hg.openjdk.java.net/openjfx/8u-dev/rt/file/8cbaf9096cda/modules/web/src/main/native/Source/JavaScriptCore/API/OpaqueJSString.cpp
String OpaqueJSString::string() const
{
    if (!this)
        return String();

    // Return a copy of the wrapped string, because the caller may make it an Identifier.
    return m_string.isolatedCopy();
}

http://hg.openjdk.java.net/openjfx/8u-dev/rt/file/8cbaf9096cda/modules/web/src/main/native/Source/JavaScriptCore/API/JSValueRef.cpp
JSValueRef JSValueMakeString(JSContextRef ctx, JSStringRef string)
{
    if (!ctx) {
        ASSERT_NOT_REACHED();
        return 0;
    }
    ExecState* exec = toJS(ctx);
    APIEntryShim entryShim(exec);

    return toRef(exec, jsString(exec, string->string()));
}


In BridgeUtils.cpp - Java_Object_to_JSValue never accomodated for the change and now leaks memory.

    if (env->IsInstanceOf(val, clString)) {
      JSStringRef value = asJSStringRef(env, (jstring) val);
      return JSValueMakeString(ctx, value);
    }

The "value" variable is getting cloned in JSValueMakeString, but it's never released.


REPRODUCIBILITY :
This bug can be reproduced always.