From pasi.eronen@hut.fi Sun Aug  3 14:32:59 1997
Date: Fri, 1 Aug 1997 21:15:48 +0300 (EEST)
From: Pasi Eronen <pasi.eronen@hut.fi>
To: htdig@sdsu.edu
Subject: htdig: Bug in Document::getdate() 

Hello!

There's a bug in HTDig 3.0.8b1's date parsing routine,
Document::getdate() in htdig/Document.cc, at least on some
platforms. As a result of this, the If-Modified-Since header
in the HTTP request is incorrect, and everything is always
read again.

I'm running IRIX 5.3 with configuration HAVE_MKTIME=1,
HAVE_TIMEGM=0, HAVE_LOCALTIME=1 and HAVE_TIMELOCAL=0.

The date itself is parsed correctly (when debug>2, the
original and translated dates printed are the same), but the
conversion to Unix timestamp doesn't correctly handle the
timezone.

I wonder why this hasn't been noticed before...? As far as 
I can tell, it should affect everyone who's not running a
BSD-variant of Unix (one with tm_gmtoff field). If you
test these patches, please tell me did they work or not!

The patches (three of them):

[removed, since they are in the .tar.gz file anyway]

You need to run autoconf after patching configure.in, of course.
And I don't think it's necessary to check for mktime() and localtime(),
or are there really systems that don't have these?

Again, comments are welcome.

Best regards,
Pasi

---
Pasi Eronen <pe@iki.fi>, 050-5123499
*** ../htdig-3.0.8b1.orig/configure.in	Mon Mar 24 00:44:03 1997
--- configure.in	Fri Aug  1 20:17:05 1997
***************
*** 53,58 ****
  AC_STRUCT_TM
  
  dnl Checks for library functions.
! AC_CHECK_FUNCS(mktime timelocal localtime gmtime)
  
  HTDIG_TOP=`pwd`
--- 53,71 ----
  AC_STRUCT_TM
  
+ dnl Check for timegm
+ AC_CHECK_FUNCS(timegm)
+ 
+ AC_MSG_CHECKING(for timezone)
+ AC_TRY_COMPILE([#include <time.h>], [return timezone;],
+   [AC_MSG_RESULT(yes);AC_DEFINE(HAVE_TIMEZONE)],
+   [AC_MSG_RESULT(no)])
+ 
+ AC_MSG_CHECKING(for altzone)
+ AC_TRY_COMPILE([#include <time.h>], [return altzone;],
+   [AC_MSG_RESULT(yes);AC_DEFINE(HAVE_ALTZONE)],
+   [AC_MSG_RESULT(no)])
+ 
  dnl Checks for library functions.
! dnl AC_CHECK_FUNCS(mktime timelocal localtime gmtime)
  
  HTDIG_TOP=`pwd`
*** ../htdig-3.0.8b1.orig/htdig/Document.cc	Sun Apr 20 18:25:28 1997
--- htdig/Document.cc	Fri Aug  1 20:49:46 1997
***************
*** 188,196 ****
  
      time_t	now = time(0);
- #if HAVE_LOCALTIME
      struct tm	*tm = localtime(&now);
- #else
-     struct tm	*tm = gmtime(&now);
- #endif
  #if HAVE_TM_GMTOFF
      tm->tm_zone = "GMT";
--- 188,192 ----
***************
*** 198,202 ****
  #endif
      mystrptime(d.get(), "%a, %d %b %Y %T", tm);
- 
      if (tm->tm_year < 0)
  	tm->tm_year += 1900;
--- 194,197 ----
***************
*** 209,217 ****
  	cout << buffer << " (" << tm->tm_year << ")" << endl;
      }
! #if HAVE_MKTIME
!     return mktime(tm);
  #else
!     return timelocal(tm);
  #endif
  }
  
--- 204,228 ----
  	cout << buffer << " (" << tm->tm_year << ")" << endl;
      }
!     time_t ret;
! #if HAVE_TM_GMTOFF
!     ret = mktime(tm);
! #elif HAVE_TIMEGM
!     ret = timegm(tm);
! #elif HAVE_TIMEZONE && HAVE_ALTZONE
!     ret = mktime(tm) - (daylight ? altzone : timezone);
! #elif HAVE_TIMEZONE
!     ret = mktime(tm) - (tm->tm_isdst ? (timezone-3600) : timezone);
  #else
! #error Must have either timezone, tm.tm_gmtoff or timegm()!
  #endif
+     if (debug > 2)
+     {
+         cout << "And converted to ";
+ 	tm = gmtime(&ret);
+ 	char	buffer[100];
+ 	strftime(buffer, sizeof(buffer), "%a, %d %b %Y %T", tm);
+ 	cout << buffer << endl;
+     }
+     return ret;
  }
  
*** ../htdig-3.0.8b1.orig/include/htconfig.h.in	Fri Feb  7 11:26:51 1997
--- include/htconfig.h.in	Fri Aug  1 20:21:36 1997
***************
*** 11,26 ****
  #define TM_IN_SYS_TIME	0
  
- /* Define if you have the mktime function.  */
- #define HAVE_MKTIME	0
- 
  /* Define if you have the timegm function.  */
  #define HAVE_TIMEGM	0
  
- /* Define if you have the localtime function.  */
- #define HAVE_LOCALTIME	0
- 
- /* Define if you have the timelocal function.  */
- #define HAVE_TIMELOCAL	0
- 
  /* Define if you have the <fcntl.h> header file.  */
  #define HAVE_FCNTL_H	0
--- 11,17 ----
***************
*** 46,49 ****
--- 37,46 ----
  /* Define if you have the tm.tm_gmtoff member of struct tm. */
  #define	HAVE_TM_GMTOFF	0
+ 
+ /* Define if you have timezone variable in time.h. */
+ #define HAVE_TIMEZONE   0
+ 
+ /* Define if you have altzone variable in time.h. */
+ #define HAVE_ALTZONE    0
  
  /* Define if you need a prototype for gethostname() */