Fix bug 315246: nsGetInterface::operator() can use an uninitialized nsresult variable, if the source fails to implement nsIInterfaceRequestor (which fires an assertion in debug builds). r=dougt, sr=bzbarsky.

xpcom/glue/nsIInterfaceRequestorUtils.cpp

@@ -51,6 +51,8 @@ nsGetInterface::operator()( const nsIID& aIID, void** aInstancePtr ) const
 
     if ( factoryPtr )
       status = factoryPtr->GetInterface(aIID, aInstancePtr);
+    else
+      status = NS_ERROR_NO_INTERFACE;
 
     if ( NS_FAILED(status) )
       *aInstancePtr = 0;