Bug#409517: dvipdfm segfault related to /etc/localtime

[Frank Küster <frank@kuesterei.ch>]

Hi Mark,

there seems to be a problem with the timezone patch that we applied
recently to our version of dvipdfm: It again segfaults with certain
timezone files.  I'm not even sure whether /etc/localtime might not be
corrupted - but still it should give an error and not segfault.  On the
other hand, dvipdfm doesn't open localtime, but query it through defined
APIs, well.

Martin Michlmayr <tbm@cyrius.com> wrote:

> * Frank Küster <frank@kuesterei.ch> [2007-02-03 21:13]:
>> Sorry, I have no idea.  But I asked because one of the last changes to
>> dvipdfm was a patch to *prevent* a segfault when used in a timezone with
>> half-hour offset from UTC.  It's in the same source file, but at a
>> different place than indicated by the trace, and I don't see the
>> relation ATM.  You can look at it at
>
> Reverting this patch (debian/patches/patch-dvipdfm-timezone-crash)
> gets rid of my segfault.

So the exact patch that we applied is at 

http://svn.debian.org/wsvn/debian-tex/tetex-bin/trunk/debian/patches/patch-dvipdfm-timezone-crash?op=file&rev=0&sc=0

and Martin's complete bug report is at 

http://bugs.debian.org/409517

Martin, do you happen to know how tzconfig handles /etc/localtime?  On
my sarge system, /etc/localtime is a symlink to a particular file below
/usr/share/zoneinfo/ (to Europe/Zurich), on my sid system it's an
ordinary file.

Is there an easy way to find out which of the preprocessor conditional
branches we're in?  I'm speaking of

+#ifdef HAVE_TM_GMTOFF  /* Preferred way to get time zone offset */
+  tz_offset = bd_time->tm_gmtoff;
+#else
+#ifdef HAVE_TIMEZONE   /* Plan B --- use external variable 'timezone'
+                       /* (may not provide correct offset for daylight savings time) */
+  tz_offset = - timezone;
+#else                  /* Last resort --- without more information, set offset to zero */
+  tz_offset = 0l;
+#endif /* HAVE_TIMEZONE */
+#endif /* HAVE_TM_GMTOFF */

The file is compiled with this command:

cc -DHAVE_CONFIG_H  -I. -I. -I.. -I./..   -O2 -c pdfdoc.c -o pdfdoc.o

TIA, Frank

-- 
Dr. Frank Küster
Single Molecule Spectroscopy, Protein Folding @ Inst. f. Biochemie, Univ. Zürich
Debian Developer (teTeX/TeXLive)