[tracker] tests: Unset TZ if it wasn't set previously

[Carlos Garnacho <carlosg src gnome org>]

commit 7e9e1027f941ff7fa3d341e73a4d29ea0b59fc11
Author: Carlos Garnacho <carlos lanedo com>
Date:   Fri Nov 22 15:09:28 2013 +0100

    tests: Unset TZ if it wasn't set previously

 tests/libtracker-common/tracker-date-time-test.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/tests/libtracker-common/tracker-date-time-test.c 
b/tests/libtracker-common/tracker-date-time-test.c
index a4bf767..f624d80 100644
--- a/tests/libtracker-common/tracker-date-time-test.c
+++ b/tests/libtracker-common/tracker-date-time-test.c
@@ -58,9 +58,11 @@ test_string_to_date (void)
        result = g_date_new ();
        g_date_set_time_t (result, result_time_t);
 
-       g_setenv ("TZ", timezone, TRUE);
        if (timezone) {
+               g_setenv ("TZ", timezone, TRUE);
                g_free (timezone);
+       } else {
+               g_unsetenv ("TZ");
        }
 
        g_assert_cmpint (g_date_get_year (expected), ==, g_date_get_year (result));