===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/cal/cal.c,v
retrieving revision 1.23
retrieving revision 1.24
diff -c -r1.23 -r1.24
*** src/usr.bin/cal/cal.c	2008/04/18 14:41:04	1.23
--- src/usr.bin/cal/cal.c	2009/01/01 21:07:17	1.24
***************
*** 1,4 ****
! /*	$OpenBSD: cal.c,v 1.23 2008/04/18 14:41:04 pyr Exp $	*/
  /*	$NetBSD: cal.c,v 1.6 1995/03/26 03:10:24 glass Exp $	*/
  
  /*
--- 1,4 ----
! /*	$OpenBSD: cal.c,v 1.24 2009/01/01 21:07:17 otto Exp $	*/
  /*	$NetBSD: cal.c,v 1.6 1995/03/26 03:10:24 glass Exp $	*/
  
  /*
***************
*** 40,46 ****
  #if 0
  static char sccsid[] = "@(#)cal.c	8.4 (Berkeley) 4/2/94";
  #else
! static const char rcsid[] = "$OpenBSD: cal.c,v 1.23 2008/04/18 14:41:04 pyr Exp $";
  #endif
  #endif /* not lint */
  
--- 40,46 ----
  #if 0
  static char sccsid[] = "@(#)cal.c	8.4 (Berkeley) 4/2/94";
  #else
! static const char rcsid[] = "$OpenBSD: cal.c,v 1.24 2009/01/01 21:07:17 otto Exp $";
  #endif
  #endif /* not lint */
  
***************
*** 146,151 ****
--- 146,152 ----
  int	day_in_week(int, int, int);
  int	day_in_year(int, int, int);
  int	week(int, int, int);
+ int	isoweek(int, int, int);
  void	j_yearly(int);
  void	monthly(int, int);
  void	trim_trailing_spaces(char *);
***************
*** 251,289 ****
  int
  week(int day, int month, int year)
  {
- 	int	leap;
- 	int	prevleap;
  	int	yearday;
  	int	firstweekday;
  	int	weekday;
  	int	firstday;
  	int	firstsunday;
  	int	shift;
  
  	yearday = day_in_year(day, month, year);
  	firstweekday = day_in_week(1, 1, year) + 1;
  	weekday = day_in_week(day, month, year) + 1;
! 	leap = leap_year(year);
! 	prevleap = leap_year(year - 1);
! 	firstday = firstsunday = day_in_year(1, 1, year);
  	firstsunday = firstday + (8 - firstweekday);
  
- 	if (!mflag)
- 		goto sunbased;
- 
- 	if (yearday <= (8 - firstweekday) && firstweekday > 4) {
- 		if (firstweekday == 5 || (firstweekday == 6 && prevleap))
- 			return (53);
- 		return (52);
- 	}
- 
- 	if (((leap ? 366 : 365) - yearday) < (4 - weekday))
- 		return (1);
- 
- 	return (((yearday + (7 - weekday) + (firstweekday - 1)) / 7)
- 	    - (firstweekday > 4));
- 
- sunbased:
  	shift = 1;
  	if (yearday < firstsunday)
  		return (1);
--- 252,273 ----
  int
  week(int day, int month, int year)
  {
  	int	yearday;
  	int	firstweekday;
  	int	weekday;
  	int	firstday;
  	int	firstsunday;
  	int	shift;
+ 	
+ 	if (mflag)
+ 		return isoweek(day, month, year);
  
  	yearday = day_in_year(day, month, year);
  	firstweekday = day_in_week(1, 1, year) + 1;
  	weekday = day_in_week(day, month, year) + 1;
! 	firstday = day_in_year(1, 1, year);
  	firstsunday = firstday + (8 - firstweekday);
  
  	shift = 1;
  	if (yearday < firstsunday)
  		return (1);
***************
*** 292,297 ****
--- 276,310 ----
  	return ((((yearday + 1) - (weekday - 1)) / 7) + shift);
  }
  
+ int
+ isoweek(int day, int month, int year)
+ {
+ 	/* http://www.tondering.dk/claus/cal/node8.html */
+ 	int a, b, c, s, e, f, g, d, n;
+ 
+ 	a = month <= 2 ? year - 1 : year;
+ 	b = a/4 - a/100 + a/400;
+ 	c = (a-1)/4 - (a-1)/100 + (a-1)/400;
+ 	s = b - c;
+ 	if (month <= 2) {
+ 		e = 0;
+ 		f = day - 1 + 31 * (month-1);
+ 	} else {
+ 		e = s + 1;
+ 		f = day + ((153 * (month-3) + 2) / 5) + 58 + s;
+ 	}
+ 	g = (a + b) % 7;
+ 	d = (f + g - e) % 7;
+ 	n = f + 3 - d;
+ 
+ 	if (n < 0)
+ 		return 53 - (g - s) / 5;
+ 	else if (n > 364 + s)
+ 		return 1;
+ 	else 
+ 		return n/7 + 1;
+ }
+ 
  void
  monthly(int month, int year)
  {
***************
*** 317,323 ****
  		trim_trailing_spaces(lineout);
  		(void)printf("%-20s", lineout);
  		if (wflag && firstday != SPACE)
! 			printf(" [%2d]", week(firstday - mflag, month, year));
  		printf("\n");
  	}
  }
--- 330,336 ----
  		trim_trailing_spaces(lineout);
  		(void)printf("%-20s", lineout);
  		if (wflag && firstday != SPACE)
! 			printf(" [%2d]", week(firstday, month, year));
  		printf("\n");
  	}
  }
***************
*** 394,400 ****
  					ascii_day(p, *dp++);
  				}
  				if (wflag && firstday != SPACE) {
! 					wn = week(firstday - mflag,
  					    month + which_cal + 1, year);
  					(void)snprintf(p, 5, "[%2d]", wn);
  					p += strlen(p);
--- 407,413 ----
  					ascii_day(p, *dp++);
  				}
  				if (wflag && firstday != SPACE) {
! 					wn = week(firstday,
  					    month + which_cal + 1, year);
  					(void)snprintf(p, 5, "[%2d]", wn);
  					p += strlen(p);