[PATCH v5 2/4] date.c: validate and set time in a helper function

["Đoàn Trần Công Danh" <congdanhqx@gmail.com>]

In a later patch, we will reuse this logic, move it to a helper, now.

While we're at it, explicit states that we intentionally ignore
old-and-defective 2nd leap second.

Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
---

Notes:
    I intentionally leave a pair of bracket around if (set_time(...))
    to reduce the noise in next patch

 date.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/date.c b/date.c
index b67c5abe24..fa39e5e8a5 100644
--- a/date.c
+++ b/date.c
@@ -539,6 +539,20 @@ static int set_date(int year, int month, int day, struct tm *now_tm, time_t now,
 	return -1;
 }
 
+static int set_time(long hour, long minute, long second, struct tm *tm)
+{
+	/* We accept 61st second because of leap second */
+	if (0 <= hour && hour <= 24 &&
+	    0 <= minute && minute < 60 &&
+	    0 <= second && second <= 60) {
+		tm->tm_hour = hour;
+		tm->tm_min = minute;
+		tm->tm_sec = second;
+		return 0;
+	}
+	return -1;
+}
+
 static int match_multi_number(timestamp_t num, char c, const char *date,
 			      char *end, struct tm *tm, time_t now)
 {
@@ -556,10 +570,7 @@ static int match_multi_number(timestamp_t num, char c, const char *date,
 	case ':':
 		if (num3 < 0)
 			num3 = 0;
-		if (num < 25 && num2 >= 0 && num2 < 60 && num3 >= 0 && num3 <= 60) {
-			tm->tm_hour = num;
-			tm->tm_min = num2;
-			tm->tm_sec = num3;
+		if (set_time(num, num2, num3, tm) == 0) {
 			break;
 		}
 		return 0;
-- 
2.26.2.384.g435bf60bd5