[gnome-control-center] sound: Avoid use-after-free of destroyed streams

[Bastien Nocera <hadess src gnome org>]

commit 8c7632e66e410c03579a9caa9abf695e36bf51fb
Author: Bastien Nocera <hadess hadess net>
Date:   Tue Aug 21 17:40:30 2012 +0100

    sound: Avoid use-after-free of destroyed streams
    
    When switching between 2 outputs that share the same device with
    different connector types, the old stream is destroyed, and a new one
    with the new connector type created.
    
    We were generating warnings because the old stream was destroyed, and
    we were trying to access it. Instead we should remove the reference
    to that old stream from the GvcLevelBars used for output and input
    levels.

 panels/sound/gvc-mixer-dialog.c |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)
---
diff --git a/panels/sound/gvc-mixer-dialog.c b/panels/sound/gvc-mixer-dialog.c
index df36237..104cb9e 100644
--- a/panels/sound/gvc-mixer-dialog.c
+++ b/panels/sound/gvc-mixer-dialog.c
@@ -959,6 +959,8 @@ bar_set_stream (GvcMixerDialog *dialog,
         g_signal_handlers_disconnect_by_func (adj, on_adjustment_value_changed, dialog);
 
         g_object_set_data (G_OBJECT (bar), "gvc-mixer-dialog-stream", stream);
+        g_object_set_data (G_OBJECT (bar), "gvc-mixer-dialog-stream-id",
+                           GUINT_TO_POINTER (gvc_mixer_stream_get_id (stream)));
         g_object_set_data (G_OBJECT (adj), "gvc-mixer-dialog-stream", stream);
         g_object_set_data (G_OBJECT (adj), "gvc-mixer-dialog-bar", bar);
 
@@ -1355,6 +1357,8 @@ remove_stream (GvcMixerDialog  *dialog,
                guint            id)
 {
         GtkWidget *bar;
+        guint output_id, input_id;
+
         bar = g_hash_table_lookup (dialog->priv->bars, GUINT_TO_POINTER (id));
         if (bar != NULL) {
                 g_hash_table_remove (dialog->priv->bars, GUINT_TO_POINTER (id));
@@ -1364,7 +1368,21 @@ remove_stream (GvcMixerDialog  *dialog,
                 if (dialog->priv->num_apps == 0) {
                         gtk_widget_show (dialog->priv->no_apps_label);
                 }
+                return;
         }
+
+	output_id = GPOINTER_TO_UINT (g_object_get_data (G_OBJECT (dialog->priv->output_bar), "gvc-mixer-dialog-stream-id"));
+	input_id = GPOINTER_TO_UINT (g_object_get_data (G_OBJECT (dialog->priv->input_bar), "gvc-mixer-dialog-stream-id"));
+
+	if (output_id == id)
+		bar = dialog->priv->output_bar;
+	else if (input_id == id)
+		bar = dialog->priv->input_bar;
+	else
+		return;
+
+	g_object_set_data (G_OBJECT (bar), "gvc-mixer-dialog-stream-id", NULL);
+	g_object_set_data (G_OBJECT (bar), "gvc-mixer-dialog-stream", NULL);
 }
 
 static void