--- a/widget/nsGUIEventIPC.h
+++ b/widget/nsGUIEventIPC.h
@@ -257,27 +257,28 @@ struct ParamTraits<nsKeyEvent>
     WriteParam(aMsg, aParam.keyCode);
     WriteParam(aMsg, aParam.charCode);
     WriteParam(aMsg, aParam.isChar);
     WriteParam(aMsg, aParam.location);
   }
 
   static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
   {
-    bool rv;
     uint32_t keyNameIndex;
-    rv = ReadParam(aMsg, aIter, static_cast<nsInputEvent*>(aResult)) &&
-         ReadParam(aMsg, aIter, &keyNameIndex) &&
-         ReadParam(aMsg, aIter, &aResult->keyCode) &&
-         ReadParam(aMsg, aIter, &aResult->charCode) &&
-         ReadParam(aMsg, aIter, &aResult->isChar) &&
-         ReadParam(aMsg, aIter, &aResult->location);
-    aResult->mKeyNameIndex =
-      static_cast<mozilla::widget::KeyNameIndex>(keyNameIndex);
-    return rv;
+    if (ReadParam(aMsg, aIter, static_cast<nsInputEvent*>(aResult)) &&
+        ReadParam(aMsg, aIter, &keyNameIndex) &&
+        ReadParam(aMsg, aIter, &aResult->keyCode) &&
+        ReadParam(aMsg, aIter, &aResult->charCode) &&
+        ReadParam(aMsg, aIter, &aResult->isChar) &&
+        ReadParam(aMsg, aIter, &aResult->location)) {
+      aResult->mKeyNameIndex =
+        static_cast<mozilla::widget::KeyNameIndex>(keyNameIndex);
+      return true;
+    }
+    return false;
   }
 };
 
 template<>
 struct ParamTraits<nsTextRangeStyle>
 {
   typedef nsTextRangeStyle paramType;