t0006: test timezone parsing

Previously, test-date simply ignored the parsed timezone and
told show_date() to use UTC. Instead, let's print out what
we actually parsed.

While we're at it, let's make it easy for tests to work in a specific
timezone.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t0006-date.sh

@@ -28,8 +28,8 @@ check_show 31449600 '12 months ago'
 
 check_parse() {
 	echo "$1 -> $2" >expect
-	test_expect_${3:-success} "parse date ($1)" "
-	test-date parse '$1' >actual &&
+	test_expect_${4:-success} "parse date ($1${3:+ TZ=$3})" "
+	TZ=${3:-$TZ} test-date parse '$1' >actual &&
 	test_cmp expect actual
 	"
 }
@@ -38,6 +38,7 @@ check_parse 2008 bad
 check_parse 2008-02 bad
 check_parse 2008-02-14 bad
 check_parse '2008-02-14 20:30:45' '2008-02-14 20:30:45 +0000'
+check_parse '2008-02-14 20:30:45 -0500' '2008-02-14 20:30:45 -0500'
 
 check_approxidate() {
 	echo "$1 -> $2 +0000" >expect

test-date.c

@@ -21,12 +21,15 @@ static void parse_dates(char **argv, struct timeval *now)
 	for (; *argv; argv++) {
 		char result[100];
 		time_t t;
+		int tz;
 
 		result[0] = 0;
 		parse_date(*argv, result, sizeof(result));
-		t = strtoul(result, NULL, 0);
-		printf("%s -> %s\n", *argv,
-			t ? show_date(t, 0, DATE_ISO8601) : "bad");
+		if (sscanf(result, "%ld %d", &t, &tz) == 2)
+			printf("%s -> %s\n",
+			       *argv, show_date(t, tz, DATE_ISO8601));
+		else
+			printf("%s -> bad\n", *argv);
 	}
 }