girepository: Add a gi_repository_new() function

It’s not intended that most people will use this, but it’s going to be
quite useful for adding unit tests — we don’t really want the unit tests
to share global state (a singleton `GIRepository`) between tests.

Signed-off-by: Philip Withnall <pwithnall@gnome.org>

Helps: #3155

girepository/girepository.c

@@ -184,7 +184,7 @@ init_globals (void)
     return;
 
   if (default_repository == NULL)
-    default_repository = g_object_new (GI_TYPE_REPOSITORY, NULL);
+    default_repository = gi_repository_new ();
 
   if (typelib_search_path == NULL)
     {
@@ -688,6 +688,23 @@ gi_repository_get_default (void)
   return get_repository (NULL);
 }
 
+/**
+ * gi_repository_new:
+ *
+ * Create a new (non-singleton) #GIRepository.
+ *
+ * Most callers should use gi_repository_get_default() instead, as a singleton
+ * repository is more useful in most situations.
+ *
+ * Returns: (transfer full): a new #GIRepository
+ * Since: 2.80
+ */
+GIRepository *
+gi_repository_new (void)
+{
+  return g_object_new (GI_TYPE_REPOSITORY, NULL);
+}
+
 /**
  * gi_repository_get_n_infos:
  * @repository: (allow-none): A #GIRepository or %NULL for the singleton

girepository/girepository.h

@@ -103,6 +103,9 @@ GType         gi_repository_get_type      (void) G_GNUC_CONST;
 GI_AVAILABLE_IN_ALL
 GIRepository *gi_repository_get_default   (void);
 
+GI_AVAILABLE_IN_ALL
+GIRepository *gi_repository_new (void);
+
 GI_AVAILABLE_IN_ALL
 void          gi_repository_prepend_search_path (const char *directory);