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

@@ -42,23 +42,25 @@
 nsresult
 nsGetInterface::operator()( const nsIID& aIID, void** aInstancePtr ) const
 {
-	nsresult status;
+  nsresult status;
 
-	if ( mSource )
-		{
-			nsCOMPtr<nsIInterfaceRequestor> factoryPtr = do_QueryInterface(mSource, &status);
-			NS_ASSERTION(factoryPtr, "Did you know you were calling |do_GetInterface()| on an object that doesn't support the |nsIInterfaceRequestor| interface?");
+  if ( mSource )
+  {
+    nsCOMPtr<nsIInterfaceRequestor> factoryPtr = do_QueryInterface(mSource, &status);
+    NS_ASSERTION(factoryPtr, "Did you know you were calling |do_GetInterface()| on an object that doesn't support the |nsIInterfaceRequestor| interface?");
 
-			if ( factoryPtr )
-				status = factoryPtr->GetInterface(aIID, aInstancePtr);
+    if ( factoryPtr )
+      status = factoryPtr->GetInterface(aIID, aInstancePtr);
+    else
+      status = NS_ERROR_NO_INTERFACE;
 
-			if ( NS_FAILED(status) )
-				*aInstancePtr = 0;
-		}
-	else
-		status = NS_ERROR_NULL_POINTER;
+    if ( NS_FAILED(status) )
+      *aInstancePtr = 0;
+  }
+  else
+    status = NS_ERROR_NULL_POINTER;
 
-	if ( mErrorPtr )
-		*mErrorPtr = status;
-	return status;
+  if ( mErrorPtr )
+    *mErrorPtr = status;
+  return status;
 }