[gedit] filebrowser: more robust check if Nautilus GSettings can be used

[Sébastien Wilmet <swilmet src gnome org>]

commit 2599cd534b3e35e7dc63567528e0dabe9f35d251
Author: Sébastien Wilmet <swilmet informatique-libre be>
Date:   Sat Jul 16 17:47:21 2022 +0200

    filebrowser: more robust check if Nautilus GSettings can be used
    
    Check if the key that we need exists.
    
    Because it's an externally provided GSettings schema, it can change
    independently from gedit.
    
    If we try to access a non-existant key, the program crashes.

 plugins/filebrowser/gedit-file-browser-plugin.c | 27 +++++++++++++++----------
 1 file changed, 16 insertions(+), 11 deletions(-)
---
diff --git a/plugins/filebrowser/gedit-file-browser-plugin.c b/plugins/filebrowser/gedit-file-browser-plugin.c
index 73d702fa4..96f257614 100644
--- a/plugins/filebrowser/gedit-file-browser-plugin.c
+++ b/plugins/filebrowser/gedit-file-browser-plugin.c
@@ -120,24 +120,26 @@ G_DEFINE_DYNAMIC_TYPE_EXTENDED (GeditFileBrowserPlugin,
                                _gedit_file_browser_widget_register_type        (type_module);          \
 )
 
-static GSettings *
-settings_try_new (const gchar *schema_id)
+static gboolean
+can_use_nautilus_gsettings (void)
 {
-       GSettings *settings = NULL;
        GSettingsSchemaSource *source;
        GSettingsSchema *schema;
+       gboolean can_use;
 
        source = g_settings_schema_source_get_default ();
+       g_assert (source != NULL);
+       schema = g_settings_schema_source_lookup (source, NAUTILUS_BASE_SETTINGS, TRUE);
 
-       schema = g_settings_schema_source_lookup (source, schema_id, TRUE);
-
-       if (schema != NULL)
+       if (schema == NULL)
        {
-               settings = g_settings_new_full (schema, NULL, NULL);
-               g_settings_schema_unref (schema);
+               return FALSE;
        }
 
-       return settings;
+       can_use = g_settings_schema_has_key (schema, NAUTILUS_CLICK_POLICY_KEY);
+
+       g_settings_schema_unref (schema);
+       return can_use;
 }
 
 static void
@@ -147,9 +149,12 @@ gedit_file_browser_plugin_init (GeditFileBrowserPlugin *plugin)
 
        plugin->priv->settings = g_settings_new (FILEBROWSER_BASE_SETTINGS);
        plugin->priv->terminal_settings = g_settings_new (TERMINAL_BASE_SETTINGS);
-       plugin->priv->nautilus_settings = settings_try_new (NAUTILUS_BASE_SETTINGS);
 
-       if (plugin->priv->nautilus_settings == NULL)
+       if (can_use_nautilus_gsettings ())
+       {
+               plugin->priv->nautilus_settings = g_settings_new (NAUTILUS_BASE_SETTINGS);
+       }
+       else
        {
                plugin->priv->nautilus_settings = g_settings_new (NAUTILUS_FALLBACK_SETTINGS);
        }