[tracker] libtracker-miner: Add extra reference around file deletion

[Carlos Garnacho <carlosg src gnome org>]

commit 4057ee9d7c051748c71fce6e4ffd15e012c5da9a
Author: Haithem BEN GHORBAL <haithem benghorbal gmail com>
Date:   Sun Feb 14 20:05:22 2016 +0100

    libtracker-miner: Add extra reference around file deletion
    
    TrackerFileNotifier::file-deleted might have removed the last reference
    to the given file, make sure it lives a bit longer for the remaining
    operations to finish.

 src/libtracker-miner/tracker-file-notifier.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)
---
diff --git a/src/libtracker-miner/tracker-file-notifier.c b/src/libtracker-miner/tracker-file-notifier.c
index d4d8ba8..76c1e40 100644
--- a/src/libtracker-miner/tracker-file-notifier.c
+++ b/src/libtracker-miner/tracker-file-notifier.c
@@ -1162,12 +1162,20 @@ monitor_item_deleted_cb (TrackerMonitor *monitor,
        /* Fetch the interned copy */
        canonical = tracker_file_system_get_file (priv->file_system,
                                                  file, file_type, NULL);
+
+       /* tracker_file_system_forget_files() might already have been
+        * called on this file. In this case, the object might become
+        * invalid when returning from g_signal_emit(). Take a
+        * reference in order to prevent that.
+        */
+       g_object_ref (canonical);
        g_signal_emit (notifier, signals[FILE_DELETED], 0, canonical);
 
        /* Remove the file from the cache (works recursively for directories) */
        tracker_file_system_forget_files (priv->file_system,
                                          canonical,
                                          G_FILE_TYPE_UNKNOWN);
+       g_object_unref (canonical);
 }
 
 static void