bad cd completion for ../ (with CHASE_DOTS unset)

bad cd completion for ../ (with CHASE_DOTS unset)

[Vincent Lefevre]

Hi,

Here, CHASE_DOTS isn't set, and my /home/lefevre/Mail directory
contains the following symbolic link, in particular:

  arc -> /users/spaces/lefevre/Mail/arc/

Now, if I do a "cd .." from the /home/lefevre/Mail/arc directory,
I go to the /home/lefevre/Mail directory as expected. But if I try
to do a completion with "cd ../[TAB]", zsh gives the completions
corresponding to the subdirectories of /users/spaces/lefevre/Mail
instead of the subdirectories of /home/lefevre/Mail, though
CHASE_DOTS isn't set. I think this is a bug.

Zsh version: 4.2.1, and I'm using the new completion system.

Please Cc to me (the Mail-Followup-To should be set correctly).

Regards,

-- 
Vincent Lefèvre <vincent@vinc17.org> - Web: <http://www.vinc17.org/>
100% validated (X)HTML - Acorn / RISC OS / ARM, free software, YP17,
Championnat International des Jeux Mathématiques et Logiques, etc.
Work: CR INRIA - computer arithmetic / SPACES project at LORIA

Re: bad cd completion for ../ (with CHASE_DOTS unset)

[Bart Schaefer]

I'm having a serious case of deja-vu over this ... I'm sure I explained 
this before, and not that long ago, but I can't find the message anywhere.

On Mon, 30 Aug 2004, Vincent Lefevre wrote:

> Here, CHASE_DOTS isn't set, and my /home/lefevre/Mail directory contains 
> [a] symbolic link [...] if I try to do a completion with "cd ../[TAB]", 
> zsh gives the completions corresponding to the subdirectories of 
> /users/spaces/lefevre/Mail instead of the subdirectories of 
> /home/lefevre/Mail, though CHASE_DOTS isn't set. I think this is a bug.

The trouble is that completion uses globbing to find the possible matching 
files, and globbing always behaves the way "cd" does with CHASE_LINKS set.

You might think that the fix is as easy as deleting "parent/.." substrings 
and replacing a leading "../" with "$PWD:h/", but the way the completion 
code is structured makes that a tricky proposition ... I don't think there 
is any variable whose value can be changed in _cd that remains visible 
down in _path_files when it starts decomposing the path at slashes and 
examining each directory ... and even if there is, doing so would probably 
generate some strange completions.

That means the only "fix" is putting a fairly ugly special-case into 
_path_files that applies only to _cd, without breaking every other path 
completion in the world.  Sven W. is incommunicado and no one else has 
been brave enough to plunge into the jungle with a machete.

(I've always thought CHASE_LINKS ought to be the one and only behavior.)

A possible workaround is to insert another function into your completer 
style, which acts as an expander to do the above-mentioned replacements on
the current word.  Thus you'd have this sort of behavior:

zsh% cd ~/Mail/arc
zsh% cd ../<TAB>
zsh% cd ~/Mail/

That is, you'd have to press TAB once to get the expansion before you can
start completing.

> Please Cc to me (the Mail-Followup-To should be set correctly).

Chortle.  Quite a, shall we say, discussion about M-F-T is in progress on 
one of the IETF lists the last couple of days.

Re: bad cd completion for ../ (with CHASE_DOTS unset)

[Vincent Lefevre]

On 2004-09-01 02:16:37 -0700, Bart Schaefer wrote:
> I'm having a serious case of deja-vu over this ... I'm sure I
> explained this before, and not that long ago, but I can't find the
> message anywhere.
[...]

Thanks for the explanation. The completion behavior should probably
be mentioned in the zshoptions(1) man page.

> (I've always thought CHASE_LINKS ought to be the one and only behavior.)

Hmm... yes, I'll change that, more because it is a security hole
(as one may easily think to be on a wrong device) than anything
else. Shouldn't CHASE_LINKS be set by default?

-- 
Vincent Lefèvre <vincent@vinc17.org> - Web: <http://www.vinc17.org/>
100% validated (X)HTML - Acorn / RISC OS / ARM, free software, YP17,
Championnat International des Jeux Mathématiques et Logiques, etc.
Work: CR INRIA - computer arithmetic / SPACES project at LORIA

Re: bad cd completion for ../ (with CHASE_DOTS unset)

[Vincent Lefevre]

On 2004-09-01 02:16:37 -0700, Bart Schaefer wrote:
> I'm having a serious case of deja-vu over this ... I'm sure I
> explained this before, and not that long ago, but I can't find the
> message anywhere.

FYI, there was a similar problem I noticed in the past:

  http://www.zsh.org/mla/users/2002/msg00180.html

Perhaps you were thinking about this one?

-- 
Vincent Lefèvre <vincent@vinc17.org> - Web: <http://www.vinc17.org/>
100% validated (X)HTML - Acorn / RISC OS / ARM, free software, YP17,
Championnat International des Jeux Mathématiques et Logiques, etc.
Work: CR INRIA - computer arithmetic / SPACES project at LORIA

Re: bad cd completion for ../ (with CHASE_DOTS unset)

[Bart Schaefer]

On Wed, 1 Sep 2004, Vincent Lefevre wrote:

>   http://www.zsh.org/mla/users/2002/msg00180.html
> 
> Perhaps you were thinking about this one?

No, I'm sure it was specifically about completion.  I must just have been
writing to someone off-list.