Edit report at http://bugs.php.net/bug.php?id=52744&edit=1
ID: 52744 Updated by: ahar...@php.net Reported by: gpap at internet dot gr -Summary: cal_days_in_month +Summary: cal_days_in_month incorrect for December 1 BCE -Status: Assigned +Status: Closed Type: Bug Package: Calendar related Operating System: all PHP Version: 5.3SVN-2010-08-30 (snap) Assigned To: aharvey Block user comment: N New Comment: This bug has been fixed in SVN. Snapshots of the sources are packaged every three hours; this change will be in the next snapshot. You can grab the snapshot at http://snaps.php.net/. Thank you for the report, and for helping us make PHP better. Thank you very much for the patch! Previous Comments: ------------------------------------------------------------------------ [2010-09-09 08:41:25] ahar...@php.net Automatic comment from SVN on behalf of aharvey Revision: http://svn.php.net/viewvc/?view=revision&revision=303203 Log: Fixed bug #52744 (cal_days_in_month incorrect for December 1 BCE). Original patch by gpap at internet dot gr. ------------------------------------------------------------------------ [2010-08-30 18:16:53] gpap at internet dot gr Description: ------------ Function cal_days_in_month returns wrong result for December 1 BCE: echo cal_days_in_month(CAL_GREGORIAN, 12, -1) returns -1721395 echo cal_days_in_month(CAL_JULIAN, 12, -1) returns -1721393 The function uses julian day count internally to calculate the day count difference between the 1st day of the supplied month and the 1st day of the next month. The next month of December 1 BCE (year -1) is January 1 CE (year 1, there is no year zero). But when cal_days_in_month calculates the next year as year+1, it does not check for year zero, so it tries to calculate the julian day for 1st January 0, which returns 0 and consequently the wrong result of days in December 1 BCE is returned. actual function code taken from latest svn snapshot php5.3-201008301230 (/ext/calendar.c): ----------------------- PHP_FUNCTION(cal_days_in_month) { long cal, month, year; struct cal_entry_t *calendar; long sdn_start, sdn_next; if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "lll", &cal, &month, &year) == FAILURE) { RETURN_FALSE; } if (cal < 0 || cal >= CAL_NUM_CALS) { php_error_docref(NULL TSRMLS_CC, E_WARNING, "invalid calendar ID %ld.", cal); RETURN_FALSE; } calendar = &cal_conversion_table[cal]; sdn_start = calendar->to_jd(year, month, 1); if (sdn_start == 0) { php_error_docref(NULL TSRMLS_CC, E_WARNING, "invalid date."); RETURN_FALSE; } sdn_next = calendar->to_jd(year, 1 + month, 1); if (sdn_next == 0) { /* if invalid, try first month of the next year... */ sdn_next = calendar->to_jd(year + 1, 1, 1); } RETURN_LONG(sdn_next - sdn_start); } ----------------------- The following correction is proposed: ----------------------- if (sdn_next == 0) { /* if invalid, try first month of the next year... */ - sdn_next = calendar->to_jd(year + 1, 1, 1); + if (year == -1) { + sdn_next = calendar->to_jd(1, 1, 1); + } else { + sdn_next = calendar->to_jd(year + 1, 1, 1); + } } ----------------------- Test script: --------------- <?php // returns -1721395 instead of 31 echo cal_days_in_month(CAL_GREGORIAN, 12, -1); // returns -1721393 instead of 31 echo cal_days_in_month(CAL_JULIAN, 12, -1); ?> Expected result: ---------------- 31 31 Actual result: -------------- -1721395 -1721393 ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/bug.php?id=52744&edit=1
