[gedit/tchaik/adwaita-css-fallback] theme: Always use Adwaita specifics as fallback

[Martin Blanchard <mablanch src gnome org>]

commit c7de780ebe9dcf32db95f9462d0cb805a83e0665
Author: Martin Blanchard <tchaik gmx com>
Date:   Sun Mar 17 13:00:32 2019 +0000

    theme: Always use Adwaita specifics as fallback
    
    Load shared and OS specific CSS resources first and fallback to Adwaita
    if no other theme specifics are found.

 gedit/gedit-app.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)
---
diff --git a/gedit/gedit-app.c b/gedit/gedit-app.c
index 24693e585..a09709ed4 100644
--- a/gedit/gedit-app.c
+++ b/gedit/gedit-app.c
@@ -678,6 +678,7 @@ theme_changed (GtkSettings *settings,
               GeditApp    *app)
 {
        GeditAppPrivate *priv;
+       GtkCssProvider *theme_provider;
 
        priv = gedit_app_get_instance_private (app);
 
@@ -697,7 +698,13 @@ theme_changed (GtkSettings *settings,
                g_clear_object (&priv->theme_provider);
        }
 
-       priv->theme_provider = load_css_from_resource (theme_css, FALSE);
+       theme_provider = load_css_from_resource (theme_css, FALSE);
+       if (theme_provider == NULL)
+       {
+               theme_provider = load_css_from_resource ("gedit.adwaita.css", TRUE);
+       }
+
+       priv->theme_provider = theme_provider;
 
        g_free (theme_css);
 }
@@ -754,7 +761,6 @@ static void
 gedit_app_startup (GApplication *application)
 {
        GeditAppPrivate *priv;
-       GtkCssProvider *css_provider;
        GtkSourceStyleSchemeManager *manager;
 #ifndef ENABLE_GVFS_METADATA
        const gchar *cache_dir;
@@ -769,8 +775,6 @@ gedit_app_startup (GApplication *application)
        gedit_debug_init ();
        gedit_debug_message (DEBUG_APP, "Startup");
 
-       setup_theme_extensions (GEDIT_APP (application));
-
 #ifndef ENABLE_GVFS_METADATA
        cache_dir = gedit_dirs_get_user_cache_dir ();
        metadata_filename = g_build_filename (cache_dir, "gedit-metadata.xml", NULL);
@@ -838,8 +842,9 @@ gedit_app_startup (GApplication *application)
 
        /* Load custom css */
        g_object_unref (load_css_from_resource ("gedit-style.css", TRUE));
-       css_provider = load_css_from_resource ("gedit-style-os.css", FALSE);
-       g_clear_object (&css_provider);
+       g_object_unref (load_css_from_resource ("gedit-style-os.css", FALSE));
+
+       setup_theme_extensions (GEDIT_APP (application));
 
        /*
         * We use the default gtksourceview style scheme manager so that plugins