GNU bug report logs - #27986
26.0.50; `rename-file' can rename files without confirmation

Previous Next

Full log

View this message in rfc822 format

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Stefan Monnier <monnier <at> IRO.UMontreal.CA>, Eli Zaretskii <eliz <at> gnu.org>
Cc: 27986 <at> debbugs.gnu.org, p.stephani2 <at> gmail.com, John Wiegley <johnw <at> gnu.org>, rms <at> gnu.org
Subject: bug#27986: 26.0.50; 'rename-file' can rename files without confirmation
Date: Wed, 16 Aug 2017 16:56:48 -0700

On 08/16/2017 03:31 PM, Stefan Monnier wrote:
>>> This should be quite rare.  The only scenario I see matching your
>>> concern is if the source is a directory, the destination is not
>>> a directory name but is an empty directory and is not a symlink, and
>>> the destination is not a descendant of  the source.  Although not
>>> impossible, this will happen so rarely that it doesn't invalidate
>>> the proposed change.
> Paul's suggestion makes a lot of sense to me, but I don't quite
> understand the above: why does the emptiness of the destination
> directory matter?

It's because the system call rename(A,B) always fails when B is a 
nonempty directory. Hence the proposed (rename-file A B) will fail if B 
is not a directory name but happens to name a nonempty directory, and 
therefore rename-file noisily fails instead of silently behaving 
differently in this case (which was Eli's concern). Conversely, if B is 
an empty directory then rename(A,B) can succeed (and thereby remove the 
old B) if all the other conditions are met.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.