if (mContextStack)
if(mContextStack) { #ifdef DEBUG JSContext* cx; nsresult rv = mContextStack->Pop(&cx); NS_ASSERTION(NS_SUCCEEDED(rv) && cx == mDebugCX, "unbalanced stack usage"); #else
AutoPushJSContext::~AutoPushJSContext(){    if (mContextStack)        mContextStack->Pop(nsnull);    if (mFrame.script)        mContext->fp = mFrame.down;}