IOExts.slurpFile fails on zero-length files

[Volker Stolz]

On Wed, May 08, 2002 at 06:10:03PM +0200, George Russell wrote:
> Volker Stolz wrote:
> [snip]
> > Unluckily it doesn't look easy to make 'hGetBuf' fail more gracefully
> > (you could read 0 bytes after all), because then still the
> > 'mallocBytes 0' in 'slurpFile' will probably fail -- to quote FreeBSD's
> > man page for malloc:
> > 
> > "It can be argued that returning a NULL pointer when asked to allocate
> >      zero bytes is a silly response to a silly question."
> I think it could be argued that FreeBSD page is wrong.  Functions should
> return consistent results where the arguments make mathematical sense, and 
> not judge particular combinations as "silly".  This GHC bug is a very good 
> example why.
> 
> I suggest that mallocBytes be altered to work when zero bytes are requested
> (you can simply keep a special pointer for this purpose, which should of
> course never be dereferenced), and 0 should be permitted as an argument to
> hGetBuf.

I don't stand on any particular OS's side w.r.t. this issue. Indeed, I'd
second your suggestion, but that would mean more changes than simply
getting slurpFile to work.

Volker