[gvfs] gdaemonfileenumerator: Fix crashes in synchronous enumerator code

[Ondrej Holy <oholy src gnome org>]

commit c155704092c1848a42539ab91cad9052c38e62af
Author: Ondrej Holy <oholy redhat com>
Date:   Mon Jul 24 12:00:09 2017 +0200

    gdaemonfileenumerator: Fix crashes in synchronous enumerator code
    
    Commit 2eae108 ported the code to GTask and slightly changed processing.
    The changes trigger the following criticals and cause crashes of some
    applications (e.g. Firefox, Thunderbird).
    GLib-GObject-CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
    
    Return TRUE from signal handlers in order to prevent further processing
    of the invocations, which cause the mentioned issues.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=784953

 client/gdaemonfileenumerator.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/client/gdaemonfileenumerator.c b/client/gdaemonfileenumerator.c
index aa30ee2..f3ba336 100644
--- a/client/gdaemonfileenumerator.c
+++ b/client/gdaemonfileenumerator.c
@@ -194,7 +194,7 @@ next_files_sync_check (GDaemonFileEnumerator *enumerator)
   g_mutex_unlock (&enumerator->next_files_mutex);
 }
 
-static void
+static gboolean
 handle_done (GVfsDBusEnumerator *object,
              GDBusMethodInvocation *invocation,
              gpointer user_data)
@@ -209,9 +209,11 @@ handle_done (GVfsDBusEnumerator *object,
   g_signal_emit (enumerator, signals[CHANGED], 0);
 
   gvfs_dbus_enumerator_complete_done (object, invocation);
+
+  return TRUE;
 }
 
-static void
+static gboolean
 handle_got_info (GVfsDBusEnumerator *object,
                  GDBusMethodInvocation *invocation,
                  GVariant *arg_infos,
@@ -248,6 +250,8 @@ handle_got_info (GVfsDBusEnumerator *object,
   g_signal_emit (enumerator, signals[CHANGED], 0);
 
   gvfs_dbus_enumerator_complete_got_info (object, invocation);
+
+  return TRUE;
 }
 
 static void