Make the succeeding parse_http_time tests more obviously right

(When the correct answer is given in terms of seconds since the
epoch, it's hard to be sure that it really is the right answer
just by reading the code.)

src/test/test_util.c

@@ -90,9 +90,15 @@ static void
 test_util_parse_http_time(void *arg)
 {
   struct tm a_time;
-
+  char b[ISO_TIME_LEN+1];
   (void)arg;
 
+#define T(s) do {                               \
+    format_iso_time(b, tor_timegm(&a_time));    \
+    tt_str_op(b, ==, (s));                      \
+    b[0]='\0';                                  \
+  } while (0)
+
   /* Test parse_http_time */
 
   test_eq(-1, parse_http_time("", &a_time));
@@ -105,26 +111,37 @@ test_util_parse_http_time(void *arg)
 
   test_eq(0, parse_http_time("Wednesday, 04 Aug 1994 00:48:22 GMT", &a_time));
   test_eq((time_t)775961302UL, tor_timegm(&a_time));
+  T("1994-08-04 00:48:22");
   test_eq(0, parse_http_time("Wednesday, 4 Aug 1994 0:48:22 GMT", &a_time));
   test_eq((time_t)775961302UL, tor_timegm(&a_time));
+  T("1994-08-04 00:48:22");
   test_eq(0, parse_http_time("Miercoles, 4 Aug 1994 0:48:22 GMT", &a_time));
   test_eq((time_t)775961302UL, tor_timegm(&a_time));
+  T("1994-08-04 00:48:22");
   test_eq(0, parse_http_time("Wednesday, 04-Aug-94 00:48:22 GMT", &a_time));
   test_eq((time_t)775961302UL, tor_timegm(&a_time));
+  T("1994-08-04 00:48:22");
   test_eq(0, parse_http_time("Wednesday, 4-Aug-94 0:48:22 GMT", &a_time));
   test_eq((time_t)775961302UL, tor_timegm(&a_time));
+  T("1994-08-04 00:48:22");
   test_eq(0, parse_http_time("Miercoles, 4-Aug-94 0:48:22 GMT", &a_time));
   test_eq((time_t)775961302UL, tor_timegm(&a_time));
+  T("1994-08-04 00:48:22");
   test_eq(0, parse_http_time("Wed Aug 04 00:48:22 1994", &a_time));
   test_eq((time_t)775961302UL, tor_timegm(&a_time));
+  T("1994-08-04 00:48:22");
   test_eq(0, parse_http_time("Wed Aug 4 0:48:22 1994", &a_time));
   test_eq((time_t)775961302UL, tor_timegm(&a_time));
+  T("1994-08-04 00:48:22");
   test_eq(0, parse_http_time("Mie Aug 4 0:48:22 1994", &a_time));
   test_eq((time_t)775961302UL, tor_timegm(&a_time));
+  T("1994-08-04 00:48:22");
   test_eq(0, parse_http_time("Sun, 1 Jan 2012 00:00:00 GMT", &a_time));
   test_eq((time_t)1325376000UL, tor_timegm(&a_time));
+  T("2012-01-01 00:00:00");
   test_eq(0, parse_http_time("Mon, 31 Dec 2012 00:00:00 GMT", &a_time));
   test_eq((time_t)1356912000UL, tor_timegm(&a_time));
+  T("2012-12-31 00:00:00");
   test_eq(-1, parse_http_time("2004-08-zz 99-99x99 GMT", &a_time));
   test_eq(-1, parse_http_time("2011-03-32 00:00:00 GMT", &a_time));
   test_eq(-1, parse_http_time("2011-03-30 24:00:00 GMT", &a_time));
@@ -134,6 +151,7 @@ test_util_parse_http_time(void *arg)
   test_eq(-1, parse_http_time("2011-00-30 23:59:59 GMT", &a_time));
   test_eq(-1, parse_http_time("2011-03-30 23:59", &a_time));
 
+#undef T
  done:
   ;
 }