[tracker] libtracker-miner: Fix TrackerFileNotifier cancellable maintenance

[Carlos Garnacho <carlosg src gnome org>]

commit 01958c044ec06fe25e1ee430891352786a034e5b
Author: Carlos Garnacho <carlosg gnome org>
Date:   Wed Feb 24 12:45:38 2016 +0100

    libtracker-miner: Fix TrackerFileNotifier cancellable maintenance
    
    Resetting and reusing is not deemed safe. It is better to create new
    cancellables and let the old ones be last unref'ed after async callbacks
    finish.

 src/libtracker-miner/tracker-file-notifier.c |   12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)
---
diff --git a/src/libtracker-miner/tracker-file-notifier.c b/src/libtracker-miner/tracker-file-notifier.c
index f6cbb48..035fbba 100644
--- a/src/libtracker-miner/tracker-file-notifier.c
+++ b/src/libtracker-miner/tracker-file-notifier.c
@@ -622,7 +622,10 @@ crawl_directory_in_current_root (TrackerFileNotifier *notifier)
                return FALSE;
 
        priv->current_index_root->current_dir = directory;
-       g_cancellable_reset (priv->cancellable);
+
+       if (priv->cancellable)
+               g_object_unref (priv->cancellable);
+       priv->cancellable = g_cancellable_new ();
 
        if ((priv->current_index_root->flags & TRACKER_DIRECTORY_FLAG_RECURSE) == 0) {
                /* Don't recurse */
@@ -1463,12 +1466,14 @@ tracker_file_notifier_finalize (GObject *object)
                g_object_unref (priv->data_provider);
        }
 
-       g_cancellable_cancel (priv->cancellable);
+       if (priv->cancellable) {
+               g_cancellable_cancel (priv->cancellable);
+               g_object_unref (priv->cancellable);
+       }
 
        g_object_unref (priv->crawler);
        g_object_unref (priv->monitor);
        g_object_unref (priv->file_system);
-       g_object_unref (priv->cancellable);
        g_clear_object (&priv->connection);
 
        if (priv->current_index_root)
@@ -1654,7 +1659,6 @@ tracker_file_notifier_init (TrackerFileNotifier *notifier)
                                             TrackerFileNotifierPrivate);
 
        priv->connection = tracker_sparql_connection_get (NULL, &error);
-       priv->cancellable = g_cancellable_new ();
 
        if (error) {
                g_warning ("Could not get SPARQL connection: %s\n",