Re: `concat' a dir and a file (was: Strange `file-name-sans-extension' behavior )

["Eli Zaretskii" <eliz@is.elta.co.il>]

> Date: Fri, 16 Aug 2002 22:51:10 -0600 (MDT)
> From: Richard Stallman <rms@gnu.org>
> 
> As far as I can see, if you don't insist on an absolute file name,
> it is correct to use concat.  As far as I can see, Eli's example
> is only an issue if you want an absolute file name:
> 
> >     It means that to produce a full file name from a relative directory
> >     "c:" and a relative file name "bar", a function should yield
> >     "c:./bar".
> 
> Eli, is c:bar an invalid file name on MSDOS?

"c:bar" is a valid file name on DOS and Windows file systems.  It
means `bar' in the default directory of the C: drive.  In other words,
it's the same as "c:./bar".

> So it seems that in the case where you are happy to have
> a non-absolute file name as the result, there is no problem.

There should be no problem if none of the functions involved convert
"c:" to "c:/".  I don't recall if that's so and don't have time to
check, but I wouldn't be surprised if Emacs primitives already take
care of this.

It's the case of application code doing (concat dir "/" file) is what
worries me.