Re: Bug in zsh-2.6-beta21

[Peter Stephenson <pws@xxxxxx>]

alainc@xxxxxxxxx wrote:
> I found the following bug in zsh-2.6-beta20 and beta21:
> 
> I typed in the following:
> 
> exec <3 <(ls -l)
> 
> --->  zsh: no such file or directory: 3
> 
> So far so good, but after that it seems that zle is broken as the up
> arrow does not retrieve the last command entered.  Instead, the cursor
> just goes up.  The tab character does not perform completion anymore,
> it just inserts a TAB.  This was on a xterm window.

Zsh thinks the <(ls -l) is a real argument, which is not unreasonable,
so it thinks it's doing a real exec.  However, the <3 open fails and
it decides it not going to do a real exec after all and returns from
execcmd().  The problem is that by that time entersubsh() has been
called to set zsh up for becoming an external program, so at the error
return lots of things (zle, monitor, job tables) are set up wrongly.

What's the answer?

1) Do we delay entersubsh() until after the redirections are handled?
I don't see why that shouldn't work.  It might fix similar potential
problems with globlist.  (Remember, it doesn't affect whether the
shell *really* becomes a subshell, just the settings.)

2) Or should this entersubsh() be delayed for safety until immediately
before the external command is executed?

2) Or is the answer to alter the behaviour of the third argument to
entersubsh (the `fake' flag) so that even less happens on an exec?  (I
believe it needs to be called in this case really just to set up the
terminal for an external command and internal settings are irrelevant
--- but in this particular case we shouldn't really be setting
anything.)



By the way, I know you're not interested, but to me `depreciate' has
only ever meant `decrease in [usually monetary] value', whatever the
dictionary says.  I've never in my life heard it used transitively ---
wrong side of the Atlantic, perhaps.

-- 
Peter Stephenson <pws@xxxxxx>       Tel: +49 33762 77366
WWW:  http://www.ifh.de/~pws/       Fax: +49 33762 77330
Deutches Electronen-Synchrotron --- Institut fuer Hochenergiephysik Zeuthen
DESY-IfH, 15735 Zeuthen, Germany.