From 993adc84d5a5be1ec2e69e8ed3db11fb220a4ad6 Mon Sep 17 00:00:00 2001 From: Jakub Zawadzki Date: Tue, 22 Apr 2014 23:13:40 +0200 Subject: Fix counting/ checking for leap years in mktime_utc() When HAVE_TIMEGM is undefined mktime_utc() might output one day shift (+86400s) for (years <= 1967 or years >= 2100) && month >= 3 { .tm_mday = 1 .tm_mon = 2 .tm_year = 67 } mktime_utc() = -89436590 // Thu Mar 2 00:00:00 UTC 1967 gmtime() = -89596800 // Wed Mar 1 00:00:00 UTC 1967 { .tm_mday = 1 .tm_mon = 2 .tm_year = 200 } mktime_utc() = 4107628800 // Tue Mar 2 00:00:00 UTC 2100 gmtime() = 4107542400 // Mon Mar 1 00:00:00 UTC 2100 Change-Id: I1a544762fa5178c8798496d7dc30a2e767919149 Reviewed-on: https://code.wireshark.org/review/1287 Reviewed-by: Anders Broman --- epan/tvbuff.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'epan/tvbuff.c') diff --git a/epan/tvbuff.c b/epan/tvbuff.c index 04a8cef71e..005cf46db8 100644 --- a/epan/tvbuff.c +++ b/epan/tvbuff.c @@ -1369,6 +1369,8 @@ mktime_utc (struct tm *tm) { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }; + + int yr; #endif #ifndef HAVE_TIMEGM @@ -1376,11 +1378,14 @@ mktime_utc (struct tm *tm) return (time_t) -1; retval = (tm->tm_year - 70) * 365; - retval += (tm->tm_year - 68) / 4; - retval += days_before[tm->tm_mon] + tm->tm_mday - 1; - if (tm->tm_year % 4 == 0 && tm->tm_mon < 2) - retval -= 1; + /* count number of leap years */ + yr = tm->tm_year + 1900; + if (tm->tm_mon + 1 < 3 && (yr % 4) == 0 && ((yr % 100) != 0 || (yr % 400) == 0)) + yr--; + retval += (((yr / 4) - (yr / 100) + (yr / 400)) - 477); /* 477 = ((1970 / 4) - (1970 / 100) + (1970 / 400)) */ + + retval += days_before[tm->tm_mon] + tm->tm_mday - 1; retval = ((((retval * 24) + tm->tm_hour) * 60) + tm->tm_min) * 60 + tm->tm_sec; #else -- cgit v1.2.3