[Xastir] Xastir segfaults: Fixed!

[Curt, WE7U]

On Mon, 4 Dec 2006, Curt, WE7U wrote:

> Here's a bit more about it:
>
>     http://curl.haxx.se/mail/lib-2002-12/0103.html
>
> It looks like we risk hanging for a long time on a slow DNS resolve
> if we disable this signal for libcurl.
>
> Our hostname.c does similar things with setting the ALARM and doing
> a siglongjmp() in the case of a timeout.  That's probably the exact
> point where libcurl code conflicts with our Xastir code.

I tweaked util.c to enable the NOSIGNAL option to libcurl if using
libcurl 7.10.0 or newer.  This means libcurl from Oct 1, 2002 or
newer.

For any of you that have had unexplained segfaults with Xastir, this
may have been the cause.  If you had libcurl compiled in and were
fetching remote maps, station tracks, etc.  ".geo" files that have a
REFRESH tag in them would be likely candidates to have triggered
this bug, like USRadar.geo perhaps.

The fix:  Don't change your .geo files, but do update to the newest
Xastir CVS and recompile.  The fix is already in the latest
lsb-xastir archive.  I'll update the SuSE RPM's shortly to include
this fix.

Note that if you are getting very slow DNS resolves for some reason
on your system, the above fix may cause Xastir to hang until you
either get an IP address or the resolver times out.  Better to slow
things down in this case than have Xastir crash though.

--
Curt, WE7U.   APRS Client Comparisons: http://www.eskimo.com/~archer
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