Bug#738339: stack-gobbling recursive exit recursion

[Barak A. Pearlmutter]

There's an issue with the qhull library package in the Debian tracker,

  For qhull>2012, the file pointer arguments for qh_new_qhull can no
  longer be null - this results in the program going into infinite
  recursion between qh_fprintf and qh_error, as qh_error tries to print,
  and qh_fprintf raises calls the error function, as the output pointer
  is null.

See https://bugs.debian.org/738339 for further details.

It's clear from the source code what's going on, but I'm not sure about
the right way to break the recursion, so I didn't try to patch around
it.  And maybe a null FILE pointer should send output to stderr instead
of exiting the program?  That's a design decision, but I would note that
the "lintian", the debian nit-picking utility, gives an
"shlib-calls-exit" for libqhull6,
http://lintian.debian.org/tags/shlib-calls-exit.html so there a pretty
strong prior among some people that libraries have no business calling
exit().

Anyway ... if you wish, please feel free to discuss the issue on the
Debian bug tracker, i.e., CC: 738339 at bugs.debian.org.  And if a patch to
address this pops up, maybe in your git repo or whatever, feel free to
send me a note and I'll rush it into the Debian package.

					Cheers,

					--Barak.

PS If you have any issues or suggestions wrt the Debian package, please
let me know.
--
Barak A. Pearlmutter
 Hamilton Institute & Dept Comp Sci, NUI Maynooth, Co. Kildare, Ireland
 http://www.bcl.hamilton.ie/~barak/