also return B_BAD_VALUE in case NULL pointer passed, please yell if you disagree with this change, but I thought the client code could look less cluttered this way

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@14817 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kits/app/LinkReceiver.cpp

@@ -239,7 +239,7 @@ LinkReceiver::Read(void *data, ssize_t size)
 	if (fReadError < B_OK)
 		return fReadError;
 
-	if (size < 1) {
+	if (data == NULL || size < 1) {
 		fReadError = B_BAD_VALUE;
 		return B_BAD_VALUE;
 	}