From ff65638bfc39898bd15170336647e8b7442e25af Mon Sep 17 00:00:00 2001
From: Maximilian Bosch <maximilian@mbosch.me>
Date: Sun, 8 Dec 2019 02:27:25 +0100
Subject: [PATCH] nixos/networkd: only set gateway if it's explicitly specified
 in the module system

---
 nixos/modules/tasks/network-interfaces-systemd.nix | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/nixos/modules/tasks/network-interfaces-systemd.nix b/nixos/modules/tasks/network-interfaces-systemd.nix
index 9ffa1089ee69..e25dc0c0b39a 100644
--- a/nixos/modules/tasks/network-interfaces-systemd.nix
+++ b/nixos/modules/tasks/network-interfaces-systemd.nix
@@ -60,8 +60,8 @@ in
       let
         domains = cfg.search ++ (optional (cfg.domain != null) cfg.domain);
         genericNetwork = override:
-          let gateway = optional (cfg.defaultGateway != null) cfg.defaultGateway.address
-            ++ optional (cfg.defaultGateway6 != null) cfg.defaultGateway6.address;
+          let gateway = optional (cfg.defaultGateway != null && (cfg.defaultGateway.address or "") != "") cfg.defaultGateway.address
+            ++ optional (cfg.defaultGateway6 != null && (cfg.defaultGateway6.address or "") != "") cfg.defaultGateway6.address;
           in optionalAttrs (gateway != [ ]) {
             routes = override [
               {