bug#68350: Segmentation fault using list-head with negative k

[Tomas Nordin]

Hello List

If this has been reported before I didn't find it. Here's the recipe:

$ guile -q
GNU Guile 3.0.8
Copyright (C) 1995-2021 Free Software Foundation, Inc.

Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
This program is free software, and you are welcome to redistribute it
under certain conditions; type `,show c' for details.

Enter `,help' for help.
scheme@(guile-user)> (list-head '(1 2 3) -1)
Segmentation fault

Argument -1 is an improper argument and an error is expected, but not a
segmentation fault.

With positive integers out of bounds I see an exception, not segfault.

This is an apt-installed guile on Debian

$ dpkg -l | grep guile
ii  guile-3.0                               3.0.8-2                             
         amd64        GNU extension language and Scheme interpreter
ii  guile-3.0-doc                           3.0.8-2                             
         all          Documentation for Guile 3.0
ii  guile-3.0-libs:amd64                    3.0.8-2                             
         amd64        Core Guile libraries

Thanks for all the work

--
Tomas