[libpeas] Keep plugins order in PeasExtensionSet

[Garrett Regier <gregier src gnome org>]

commit e07d2844b6ab78ceefd4e2f746967b85c0da3236
Author: Garrett Regier <garrettregier gmail com>
Date:   Wed Nov 18 00:38:11 2015 -0800

    Keep plugins order in PeasExtensionSet
    
    The PeasEngine orders the plugin-list based
    on dependencies and it should be maintained.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=758446

 libpeas/peas-extension-set.c  |   30 +++++++++++++------------
 tests/libpeas/extension-set.c |   48 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 14 deletions(-)
---
diff --git a/libpeas/peas-extension-set.c b/libpeas/peas-extension-set.c
index 302c149..cb3f9cc 100644
--- a/libpeas/peas-extension-set.c
+++ b/libpeas/peas-extension-set.c
@@ -94,7 +94,7 @@ struct _PeasExtensionSetPrivate {
   guint n_parameters;
   GParameter *parameters;
 
-  GList *extensions;
+  GQueue extensions;
 };
 
 typedef struct {
@@ -219,11 +219,11 @@ add_extension (PeasExtensionSet *set,
                                          priv->n_parameters,
                                          priv->parameters);
 
-  item = (ExtensionItem *) g_slice_new (ExtensionItem);
+  item = g_slice_new (ExtensionItem);
   item->info = info;
   item->exten = exten;
 
-  priv->extensions = g_list_prepend (priv->extensions, item);
+  g_queue_push_tail (&priv->extensions, item);
   g_signal_emit (set, signals[EXTENSION_ADDED], 0, info, exten);
 }
 
@@ -244,16 +244,16 @@ remove_extension (PeasExtensionSet *set,
 {
   PeasExtensionSetPrivate *priv = GET_PRIV (set);
   GList *l;
-  ExtensionItem *item;
 
-  for (l = priv->extensions; l; l = l->next)
+  for (l = priv->extensions.head; l != NULL; l = l->next)
     {
-      item = (ExtensionItem *) l->data;
+      ExtensionItem *item = l->data;
+
       if (item->info != info)
         continue;
 
       remove_extension_item (set, item);
-      priv->extensions = g_list_delete_link (priv->extensions, l);
+      g_queue_delete_link (&priv->extensions, l);
       return;
     }
 }
@@ -261,6 +261,9 @@ remove_extension (PeasExtensionSet *set,
 static void
 peas_extension_set_init (PeasExtensionSet *set)
 {
+  PeasExtensionSetPrivate *priv = GET_PRIV (set);
+
+  g_queue_init (&priv->extensions);
 }
 
 static void
@@ -296,13 +299,12 @@ peas_extension_set_dispose (GObject *object)
   PeasExtensionSetPrivate *priv = GET_PRIV (set);
   GList *l;
 
-  if (priv->extensions != NULL)
+  if (priv->extensions.length > 0)
     {
-      for (l = priv->extensions; l != NULL; l = l->next)
+      for (l = priv->extensions.tail; l != NULL; l = l->prev)
         remove_extension_item (set, (ExtensionItem *) l->data);
 
-      g_list_free (priv->extensions);
-      priv->extensions = NULL;
+      g_queue_clear (&priv->extensions);
     }
 
   if (priv->parameters != NULL)
@@ -329,7 +331,7 @@ peas_extension_set_call_real (PeasExtensionSet *set,
   GList *l;
   GIArgument dummy;
 
-  for (l = priv->extensions; l; l = l->next)
+  for (l = priv->extensions.head; l != NULL; l = l->next)
     {
       ExtensionItem *item = (ExtensionItem *) l->data;
       ret = peas_extension_callv (item->exten, method_name, args, &dummy) && ret;
@@ -455,7 +457,7 @@ peas_extension_set_get_extension (PeasExtensionSet *set,
   g_return_val_if_fail (PEAS_IS_EXTENSION_SET (set), NULL);
   g_return_val_if_fail (info != NULL, NULL);
 
-  for (l = priv->extensions; l != NULL; l = l->next)
+  for (l = priv->extensions.head; l != NULL; l = l->next)
     {
       ExtensionItem *item = l->data;
 
@@ -594,7 +596,7 @@ peas_extension_set_foreach (PeasExtensionSet            *set,
   g_return_if_fail (PEAS_IS_EXTENSION_SET (set));
   g_return_if_fail (func != NULL);
 
-  for (l = priv->extensions; l; l = l->next)
+  for (l = priv->extensions.head; l != NULL; l = l->next)
     {
       ExtensionItem *item = (ExtensionItem *) l->data;
 
diff --git a/tests/libpeas/extension-set.c b/tests/libpeas/extension-set.c
index 93d6339..c4d4d3c 100644
--- a/tests/libpeas/extension-set.c
+++ b/tests/libpeas/extension-set.c
@@ -286,6 +286,52 @@ test_extension_set_foreach (PeasEngine *engine)
   g_object_unref (extension_set);
 }
 
+static void
+ordering_cb (PeasExtensionSet  *set,
+             PeasPluginInfo    *info,
+             PeasExtension     *extension,
+             GList            **order)
+{
+  const gchar *order_module_name = (const gchar *) (*order)->data;
+
+  g_assert_cmpstr (order_module_name, ==,
+                   peas_plugin_info_get_module_name (info));
+  *order = g_list_delete_link (*order, *order);
+}
+
+static void
+test_extension_set_ordering (PeasEngine *engine)
+{
+  guint i;
+  GList *foreach_order = NULL;
+  GList *dispose_order = NULL;
+  PeasExtensionSet *extension_set;
+
+  for (i = 0; i < G_N_ELEMENTS (loadable_plugins); ++i)
+    {
+      /* Use descriptive names to make an assert more informative */
+      foreach_order = g_list_append (foreach_order,
+                                     (gpointer) loadable_plugins[i]);
+      dispose_order = g_list_prepend (dispose_order,
+                                      (gpointer) loadable_plugins[i]);
+    }
+
+  extension_set = testing_extension_set_new (engine, NULL);
+
+  peas_extension_set_foreach (extension_set,
+                              (PeasExtensionSetForeachFunc) ordering_cb,
+                              &foreach_order);
+  g_assert (foreach_order == NULL);
+
+
+  g_signal_connect (extension_set,
+                    "extension-removed",
+                    G_CALLBACK (ordering_cb),
+                    &dispose_order);
+  g_object_unref (extension_set);
+  g_assert (dispose_order == NULL);
+}
+
 int
 main (int    argc,
       char **argv)
@@ -310,6 +356,8 @@ main (int    argc,
 
   TEST ("foreach", foreach);
 
+  TEST ("ordering", ordering);
+
 #undef TEST
 
   return testing_run_tests ();