Bug 1311687 - Pop eval context on early returns. r=peterv

Make sure the eval context stack is cleaned up on failure.

MozReview-Commit-ID: AUNen1xt9He

--HG--
extra : rebase_source : 405afaf2e3e77a2fb4761440f837645cf5a8c18e

dom/xslt/xslt/txExecutionState.cpp

@@ -227,33 +227,47 @@ txExecutionState::getVariable(int32_t aNamespace, nsIAtom* aLName,
         rv = var->mExpr->evaluate(getEvalContext(), &aResult);
         mLocalVariables = oldVars;
 
-        NS_ENSURE_SUCCESS(rv, rv);
+        if (NS_FAILED(rv)) {
+          popEvalContext();
+          return rv;
+        }
     }
     else {
         nsAutoPtr<txRtfHandler> rtfHandler(new txRtfHandler);
-        NS_ENSURE_TRUE(rtfHandler, NS_ERROR_OUT_OF_MEMORY);
 
         rv = pushResultHandler(rtfHandler);
-        NS_ENSURE_SUCCESS(rv, rv);
-        
+        if (NS_FAILED(rv)) {
+          popEvalContext();
+          return rv;
+        }
+
         rtfHandler.forget();
 
         txInstruction* prevInstr = mNextInstruction;
         // set return to nullptr to stop execution
         mNextInstruction = nullptr;
         rv = runTemplate(var->mFirstInstruction);
-        NS_ENSURE_SUCCESS(rv, rv);
+        if (NS_FAILED(rv)) {
+          popEvalContext();
+          return rv;
+        }
 
         pushTemplateRule(nullptr, txExpandedName(), nullptr);
         rv = txXSLTProcessor::execute(*this);
-        NS_ENSURE_SUCCESS(rv, rv);
+        if (NS_FAILED(rv)) {
+          popEvalContext();
+          return rv;
+        }
 
         popTemplateRule();
 
         mNextInstruction = prevInstr;
         rtfHandler = (txRtfHandler*)popResultHandler();
         rv = rtfHandler->getAsRTF(&aResult);
-        NS_ENSURE_SUCCESS(rv, rv);
+        if (NS_FAILED(rv)) {
+          popEvalContext();
+          return rv;
+        }
     }
     popEvalContext();