[sound-juicer] Fix memory leak in EggPlayPreview

[Phillip Wood <pwood src gnome org>]

commit b90c96e27929e9fa29fe61c3f97150e4bdd827ff
Author: Phillip Wood <phillip wood dunelm org uk>
Date:   Thu Feb 11 14:38:47 2016 +0000

    Fix memory leak in EggPlayPreview
    
    Make sure the tags and tag list are freed properly when handling tag
    messages and when the instance is freed.

 src/egg-play-preview.c |   53 +++++++++++++++++++++++++++++-------------------
 1 files changed, 32 insertions(+), 21 deletions(-)
---
diff --git a/src/egg-play-preview.c b/src/egg-play-preview.c
index e80d536..e7d1a08 100644
--- a/src/egg-play-preview.c
+++ b/src/egg-play-preview.c
@@ -354,20 +354,10 @@ egg_play_preview_dispose (GObject *object)
 
        _clear_pipeline (play_preview);
 
-       if (priv->title) {
-               g_free (priv->title);
-               priv->title = NULL;
-       }
-
-       if (priv->album) {
-               g_free (priv->album);
-               priv->album = NULL;
-       }
-
-       if (priv->uri) {
-               g_free (priv->uri);
-               priv->uri = NULL;
-       }
+       g_clear_pointer (&priv->title, g_free);
+       g_clear_pointer (&priv->artist, g_free);
+       g_clear_pointer (&priv->album, g_free);
+       g_clear_pointer (&priv->uri, g_free);
 
        if (priv->timeout_id != 0) {
                g_source_remove (priv->timeout_id);
@@ -720,7 +710,8 @@ static gboolean
 _process_bus_messages (GstBus *bus, GstMessage *msg, EggPlayPreview *play_preview)
 {
        EggPlayPreviewPrivate *priv;
-       GstTagList *tag_list;
+       GstTagList *tag_list = NULL;
+       gchar *title = NULL, *artist = NULL, *album = NULL;
        gint64 duration;
        GstState state;
        GstStateChangeReturn result;
@@ -745,13 +736,33 @@ _process_bus_messages (GstBus *bus, GstMessage *msg, EggPlayPreview *play_previe
 
        case GST_MESSAGE_TAG:
                gst_message_parse_tag (msg, &tag_list);
-               gst_tag_list_get_string (tag_list, GST_TAG_TITLE, &priv->title);
-               gst_tag_list_get_string (tag_list, GST_TAG_ARTIST, &priv->artist);
-               gst_tag_list_get_string (tag_list, GST_TAG_ALBUM, &priv->album);
+               gst_tag_list_get_string (tag_list, GST_TAG_TITLE, &title);
+               gst_tag_list_get_string (tag_list, GST_TAG_ARTIST, &artist);
+               gst_tag_list_get_string (tag_list, GST_TAG_ALBUM, &album);
+               gst_tag_list_unref (tag_list);
+
+               if (g_strcmp0 (title, priv->title) != 0) {
+                       g_free (priv->title);
+                       priv->title = title;
+                       g_object_notify (G_OBJECT (play_preview), "title");
+               } else {
+                       g_free (title);
+               }
+               if (g_strcmp0 (artist, priv->artist) != 0) {
+                       g_free (priv->artist);
+                       priv->artist = artist;
+                       g_object_notify (G_OBJECT (play_preview), "artist");
+               } else {
+                       g_free (artist);
+               }
 
-               g_object_notify (G_OBJECT (play_preview), "title");
-               g_object_notify (G_OBJECT (play_preview), "artist");
-               g_object_notify (G_OBJECT (play_preview), "album");
+               if (g_strcmp0 (album, priv->album) != 0) {
+                       g_free (priv->album);
+                       priv->album = album;
+                       g_object_notify (G_OBJECT (play_preview), "album");
+               } else {
+                       g_free (album);
+               }
 
                _ui_update_tags (play_preview);
                break;