[evolution-data-server/gnome-3-8] Bug 699027 - Crash in e_cal_backend_file_get_backend_property()

[Matthew Barnes <mbarnes src gnome org>]

commit ce75ee9c3ede7f3aef0452e6dc5a861bf76ec992
Author: Frederic Peters <fpeters 0d be>
Date:   Sun Apr 28 09:31:57 2013 -0400

    Bug 699027 - Crash in e_cal_backend_file_get_backend_property()

 calendar/backends/file/e-cal-backend-file.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/calendar/backends/file/e-cal-backend-file.c b/calendar/backends/file/e-cal-backend-file.c
index dfad812..f3d24aa 100644
--- a/calendar/backends/file/e-cal-backend-file.c
+++ b/calendar/backends/file/e-cal-backend-file.c
@@ -514,10 +514,14 @@ e_cal_backend_file_get_backend_property (ECalBackendSync *backend,
                g_object_unref (comp);
        } else if (g_str_equal (prop_name, CAL_BACKEND_PROPERTY_REVISION)) {
                icalproperty *prop;
+               const gchar *revision = NULL;
 
                /* This returns NULL if backend lacks an icalcomp. */
                prop = ensure_revision (E_CAL_BACKEND_FILE (backend));
-               *prop_value = g_strdup (icalproperty_get_x (prop));
+               if (prop != NULL)
+                       revision = icalproperty_get_x (prop);
+
+               *prop_value = g_strdup (revision);
        } else {
                processed = FALSE;
        }