date.c: allow compact version of ISO-8601 datetime

Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

date.c

@@ -687,6 +687,20 @@ static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt
 		n++;
 	} while (isdigit(date[n]));
 
+	/* 8 digits, compact style of ISO-8601's date: YYYYmmDD */
+	/* 6 digits, compact style of ISO-8601's time: HHMMSS */
+	if (n == 8 || n == 6) {
+		unsigned int num1 = num / 10000;
+		unsigned int num2 = (num % 10000) / 100;
+		unsigned int num3 = num % 100;
+		if (n == 8)
+			set_date(num1, num2, num3, NULL, time(NULL), tm);
+		else if (n == 6 && set_time(num1, num2, num3, tm) == 0 &&
+			 *end == '.' && isdigit(end[1]))
+			strtoul(end + 1, &end, 10);
+		return end - date;
+	}
+
 	/* Four-digit year or a timezone? */
 	if (n == 4) {
 		if (num <= 1400 && *offset == -1) {

t/t0006-date.sh

@@ -82,6 +82,9 @@ 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_parse '2008.02.14 20:30:45 -0500' '2008-02-14 20:30:45 -0500'
+check_parse '20080214T203045-04:00' '2008-02-14 20:30:45 -0400'
+check_parse '20080214T203045 -04:00' '2008-02-14 20:30:45 -0400'
+check_parse '20080214T203045.019-04:00' '2008-02-14 20:30:45 -0400'
 check_parse '2008-02-14 20:30:45.019-04:00' '2008-02-14 20:30:45 -0400'
 check_parse '2008-02-14 20:30:45 -0015' '2008-02-14 20:30:45 -0015'
 check_parse '2008-02-14 20:30:45 -5' '2008-02-14 20:30:45 +0000'