Re: cd bugs

[Peter Stephenson <pws@csr.com>]

On Wed, 15 Jul 2009 03:28:53 +0000 (UTC)
Eric Blake <ebb9@byu.net> wrote:
> Eric Blake <ebb9 <at> byu.net> writes:
> 
> > $ zsh -c 'emulate -R sh; CDPATH=///; cd eblake; /bin/pwd'
> > //eblake
> > $ bash -c 'CDPATH=///; cd eblake; /bin/pwd'
> > bash: line 0: cd: eblake: No such file or directory
> > /tmp
> > $
> 
> Of the three examples mentioned in this thread, this one is definitely a bug,
> but one that only affects platforms where // is special (which, based on the
> __CYGWIN__ conditional in the source, appears to be just cygwin).

Thanks, I've committed it.

> Actually, in looking at this patch again, I'm starting to wonder if it
> might be better to teach tricat that if the first argument ends in '/'
> and the second argument is exactly "/", then it does not need to use the
> second argument; this would certainly make it touch all code paths that
> do file name concatenation, rather than trying to change down and protect
> every caller of tricat with __CYGWIN__ conditionals.  In other words,
> there are probably also bugs with ~ expansion when $HOME is exactly / or
> //, as well as other potential gotchas with // handling that I haven't
> even investigated here.

It would probably be better to introduce a pathtricat(), since tricat()
isn't necessarily tied to paths; but it's possible similar issues occur
with dupstring() or ztrdup(), too.  It's certainly a danger this could
happen elsewhere.

-- 
Peter Stephenson <pws@csr.com>            Software Engineer
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