PulseAudio: update existing item rather than delete and replace

This avoids the infamous VLC playlist bug whereby the playlist stops if
the current item is deleted. It turns out PulseAudio tends to "update"
a source right after VLC opens it, and then VLC stopped playing almost
as soon as it started.
(cherry picked from commit 5678c1900b38babcbdf453fcbf3ee4f9a863e594)

modules/services_discovery/pulse.c

@@ -119,7 +119,6 @@ static void DestroySource (void *data)
 {
     struct device *d = data;
 
-    if (d->sd)
     services_discovery_RemoveItem (d->sd, d->item);
     vlc_gc_decref (d->item);
     free (d);
@@ -164,18 +163,22 @@ static int AddSource (services_discovery_t *sd, const pa_source_info *info)
     }
     d->index = info->index;
     d->item = item;
-    d->sd = NULL;
 
     struct device **dp = tsearch (d, &sys->root, cmpsrc);
     if (dp == NULL) /* Out-of-memory */
     {
-        DestroySource (d);
+        free (d);
+        vlc_gc_decref (item);
         return -1;
     }
-    if (*dp != d) /* Replace existing source */
+    if (*dp != d) /* Update existing source */
     {
-        DestroySource (*dp);
-        *dp = d;
+        free (d);
+        d = *dp;
+        input_item_SetURI (d->item, item->psz_uri);
+        input_item_SetName (d->item, item->psz_name);
+        vlc_gc_decref (item);
+        return 0;
     }
 
     const char *card = pa_proplist_gets(info->proplist, "device.product.name");