[gnome-online-accounts/224-ability-to-restrict-which-services-of-a-particular-account-type-are-available] goaprovider: Prefer goa.conf over GSettings for enabled providers

[Milan Crha <mcrha src gnome org>]

commit 684897d4516b086aa0b4b27fa0298d2ea5f7fbcb
Author: Milan Crha <mcrha redhat com>
Date:   Thu Sep 29 21:36:46 2022 +0200

    goaprovider: Prefer goa.conf over GSettings for enabled providers
    
    This prefers
    
    [providers]
    enable=owncloud,kerberos
    
    in goa.conf in the system config directory over GSettings' value,
    if present, to limit which providers can be enabled. When the goa.conf
    doesn't exist, or the group/key does not exist, then the value from
    the GSettings is used instead.
    
    Related to https://gitlab.gnome.org/GNOME/gnome-online-accounts/-/issues/224

 data/org.gnome.online-accounts.gschema.xml |  2 ++
 src/goabackend/goaprovider.c               | 30 +++++++++++++++++++++++++-----
 2 files changed, 27 insertions(+), 5 deletions(-)
---
diff --git a/data/org.gnome.online-accounts.gschema.xml b/data/org.gnome.online-accounts.gschema.xml
index 46b79b21..4419d617 100644
--- a/data/org.gnome.online-accounts.gschema.xml
+++ b/data/org.gnome.online-accounts.gschema.xml
@@ -6,6 +6,8 @@
       <summary>List of providers that are allowed to be loaded</summary>
       <description>
         A list of strings representing the providers that are allowed to be loaded (default: 'all'). This is 
only evaluated on startup.
+
+        Deprecated: use goa.conf in the system config directory instead, with a key [providers] enable=all 
instead. The key is comma-separated list of the provider names.
       </description>
     </key>
   </schema>
diff --git a/src/goabackend/goaprovider.c b/src/goabackend/goaprovider.c
index 89e01f10..939040a2 100644
--- a/src/goabackend/goaprovider.c
+++ b/src/goabackend/goaprovider.c
@@ -1116,14 +1116,35 @@ goa_provider_ensure_builtins_loaded (void)
 
   if (g_once_init_enter (&once_init_value))
     {
-      GSettings *settings;
-      gchar **whitelisted_providers;
+      GKeyFile *goa_conf;
+      gchar **whitelisted_providers = NULL;
       guint i;
       guint j;
       gboolean all = FALSE;
 
-      settings = g_settings_new (GOA_SETTINGS_SCHEMA);
-      whitelisted_providers = g_settings_get_strv (settings, GOA_SETTINGS_WHITELISTED_PROVIDERS);
+      goa_conf = goa_util_open_goa_conf ();
+      if (goa_conf)
+        {
+          whitelisted_providers = g_key_file_get_string_list (goa_conf, "providers", "enable", NULL, NULL);
+          /* Let the empty array be like 'all' */
+          if (whitelisted_providers && !*whitelisted_providers)
+            {
+              g_strfreev (whitelisted_providers);
+              whitelisted_providers = g_new0 (gchar *, 2);
+              whitelisted_providers[0] = g_strdup ("all");
+              whitelisted_providers[1] = NULL;
+            }
+          g_clear_pointer (&goa_conf, g_key_file_free);
+        }
+
+      if (!whitelisted_providers)
+        {
+          GSettings *settings;
+
+          settings = g_settings_new (GOA_SETTINGS_SCHEMA);
+          whitelisted_providers = g_settings_get_strv (settings, GOA_SETTINGS_WHITELISTED_PROVIDERS);
+          g_object_unref (settings);
+        }
 
       /* Enable everything if there is 'all'. */
       for (i = 0; whitelisted_providers[i] != NULL; i++)
@@ -1162,7 +1183,6 @@ goa_provider_ensure_builtins_loaded (void)
 
     cleanup:
       g_strfreev (whitelisted_providers);
-      g_object_unref (settings);
       g_once_init_leave (&once_init_value, 1);
     }
 }