Re: [PATCH] strbuf: support long paths w/o read rights in strbuf_getcwd() on FreeBSD

[Junio C Hamano <gitster@pobox.com>]

René Scharfe <l.s.r@web.de> writes:

> FreeBSD implements getcwd(3) as a syscall, but falls back to a version
> based on readdir(3) if it fails for some reason.  The latter requires
> permissions to read and execute path components, while the former does
> not.  That means that if our buffer is too small and we're missing
> rights we could get EACCES, but we may succeed with a bigger buffer.

WOW.  Just WOW.  Looking at the debugging exchange from the
sideline, I didn't expect this end result.

> Keep retrying if getcwd(3) indicates lack of permissions until our
> buffer can fit PATH_MAX bytes, as that's the maximum supported by the
> syscall on FreeBSD anyway.  This way we do what we can to be able to
> benefit from the syscall, but we also won't loop forever if there is a
> real permission issue.
>
> This fixes a regression introduced with 7333ed17 (setup: convert
> setup_git_directory_gently_1 et al. to strbuf, 2014-07-28) for paths
> longer than 127 bytes with components that miss read or execute
> permissions (e.g. 0711 on /home for privacy reasons); we used a fixed
> PATH_MAX-sized buffer before.
>
> Reported-by: Zenobiusz Kunegunda <zenobiusz.kunegunda@interia.pl>
> Signed-off-by: Rene Scharfe <l.s.r@web.de>
> ---


Nicely analysed and fixed (or is the right word "worked around"?)

Thanks, will queue.