From 9cf93ba13587dba8116fa99279e51cf60c7bde88 Mon Sep 17 00:00:00 2001
From: Scott Olson <scott@solson.me>
Date: Thu, 18 Feb 2016 22:10:43 -0600
Subject: [PATCH] Simplify fetchurl assertion logic.

The two lines I removed technically assert the exact same thing, since `!a -> b`
is equivalent to `a || b`. So, I replaced the two lines with the more symmetric
form to make it clearer.
---
 pkgs/build-support/fetchurl/default.nix | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/pkgs/build-support/fetchurl/default.nix b/pkgs/build-support/fetchurl/default.nix
index 804974954d1..2c802bb3679 100644
--- a/pkgs/build-support/fetchurl/default.nix
+++ b/pkgs/build-support/fetchurl/default.nix
@@ -85,8 +85,7 @@ in
 }:
 
 assert builtins.isList urls;
-assert urls != [] -> url == "";
-assert url != "" -> urls == [];
+assert urls == [] || url == "";
 
 
 let