From: Jeremy Soller <jeremy@system76.com>
Date: Wed, 20 Jun 2018 19:22:06 +0200
Subject: Add support for GDM theme alternatives

GNOME vanilla and systemd76 derivative ships their own GDM theme.

This allows to provide alternative gresource file for gdm3 that must contain
a `gdm3.css` stylesheet that will be applied.

Bug: https://bugzilla.gnome.org/show_bug.cgi?id=787454
Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1715722
Last-Update: 2017-09-08
---
 data/gnome-shell-theme.gresource.xml | 1 +
 js/ui/sessionMode.js                 | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/data/gnome-shell-theme.gresource.xml b/data/gnome-shell-theme.gresource.xml
index 8a4948e..5fbb672 100644
--- a/data/gnome-shell-theme.gresource.xml
+++ b/data/gnome-shell-theme.gresource.xml
@@ -9,6 +9,7 @@
     <file>checkbox-off-focused.svg</file>
     <file>checkbox-off-light.svg</file>
     <file>checkbox-off.svg</file>
+    <file alias="gdm.css">gnome-shell-dark.css</file>
     <file>gnome-shell-dark.css</file>
     <file>gnome-shell-light.css</file>
     <file>gnome-shell-high-contrast.css</file>
diff --git a/js/ui/sessionMode.js b/js/ui/sessionMode.js
index 8e30a66..e27f4fa 100644
--- a/js/ui/sessionMode.js
+++ b/js/ui/sessionMode.js
@@ -53,6 +53,8 @@ const _modes = {
 
     'gdm': {
         hasNotifications: true,
+        stylesheetName: 'gdm.css',
+        themeResourceName: 'gdm-theme.gresource',
         isGreeter: true,
         isPrimary: true,
         unlockDialog: LoginDialog,