[libgdata] core: Allow the GDataFeed type to be passed to _gdata_feed_new()

[Philip Withnall <pwithnall src gnome org>]

commit 18edbc4e90f582bc67b08f6158c97666ebd8acaf
Author: Philip Withnall <philip tecnocode co uk>
Date:   Fri Dec 12 23:15:45 2014 +0000

    core: Allow the GDataFeed type to be passed to _gdata_feed_new()
    
    This will be used internally later to support constructing custom empty
    feeds for pagination purposes.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=741345

 gdata/gdata-batch-operation.c |    3 ++-
 gdata/gdata-feed.c            |   14 ++++++++++----
 gdata/gdata-private.h         |    5 ++++-
 3 files changed, 16 insertions(+), 6 deletions(-)
---
diff --git a/gdata/gdata-batch-operation.c b/gdata/gdata-batch-operation.c
index 1959f90..feb6128 100644
--- a/gdata/gdata-batch-operation.c
+++ b/gdata/gdata-batch-operation.c
@@ -616,7 +616,8 @@ gdata_batch_operation_run (GDataBatchOperation *self, GCancellable *cancellable,
 
        /* Build the request */
        g_get_current_time (&updated);
-       feed = _gdata_feed_new ("Batch operation feed", "batch1", updated.tv_sec);
+       feed = _gdata_feed_new (GDATA_TYPE_FEED, "Batch operation feed",
+                               "batch1", updated.tv_sec);
 
        g_hash_table_iter_init (&iter, priv->operations);
        while (g_hash_table_iter_next (&iter, &op_id, (gpointer*) &op) == TRUE) {
diff --git a/gdata/gdata-feed.c b/gdata/gdata-feed.c
index 0cc6c73..68ed7a0 100644
--- a/gdata/gdata-feed.c
+++ b/gdata/gdata-feed.c
@@ -647,26 +647,32 @@ post_parse_json (GDataParsable *parsable, gpointer user_data, GError **error)
 
 /*
  * _gdata_feed_new:
+ * @feed_type: the type of #GDataFeed subclass
  * @title: the feed's title
  * @id: the feed's ID
  * @updated: when the feed was last updated
  *
- * Creates a new #GDataFeed with the bare minimum of data to be valid.
+ * Creates a new #GDataFeed or subclass with the bare minimum of data to be
+ * valid.
  *
  * Return value: a new #GDataFeed
  *
- * Since: 0.6.0
+ * Since: UNRELEASED
  */
 GDataFeed *
-_gdata_feed_new (const gchar *title, const gchar *id, gint64 updated)
+_gdata_feed_new (GType feed_type,
+                 const gchar *title,
+                 const gchar *id,
+                 gint64 updated)
 {
        GDataFeed *feed;
 
+       g_return_val_if_fail (g_type_is_a (feed_type, GDATA_TYPE_FEED), NULL);
        g_return_val_if_fail (title != NULL, NULL);
        g_return_val_if_fail (id != NULL, NULL);
        g_return_val_if_fail (updated >= 0, NULL);
 
-       feed = g_object_new (GDATA_TYPE_FEED, NULL);
+       feed = g_object_new (feed_type, NULL);
        feed->priv->title = g_strdup (title);
        feed->priv->id = g_strdup (id);
        feed->priv->updated = updated;
diff --git a/gdata/gdata-private.h b/gdata/gdata-private.h
index ed19520..f470561 100644
--- a/gdata/gdata-private.h
+++ b/gdata/gdata-private.h
@@ -89,7 +89,10 @@ G_GNUC_INTERNAL void _gdata_parsable_string_append_escaped (GString *xml_string,
 G_GNUC_INTERNAL gboolean _gdata_parsable_is_constructed_from_xml (GDataParsable *self);
 
 #include "gdata-feed.h"
-G_GNUC_INTERNAL GDataFeed *_gdata_feed_new (const gchar *title, const gchar *id, gint64 updated) 
G_GNUC_WARN_UNUSED_RESULT;
+G_GNUC_INTERNAL GDataFeed *_gdata_feed_new (GType feed_type,
+                                            const gchar *title,
+                                            const gchar *id,
+                                            gint64 updated) G_GNUC_WARN_UNUSED_RESULT;
 G_GNUC_INTERNAL GDataFeed *_gdata_feed_new_from_xml (GType feed_type, const gchar *xml, gint length, GType 
entry_type,
                                                      GDataQueryProgressCallback progress_callback, gpointer 
progress_user_data,
                                                      GError **error) G_GNUC_WARN_UNUSED_RESULT G_GNUC_MALLOC;