shell.el: directory tracking can't cope with subshells

shell.el: directory tracking can't cope with subshells

[era eriksson]

This bug report will be sent to the Free Software Foundation,
 not to your local site managers!!
Please write in English, because the Emacs maintainers do not have
translators to read other languages for them.

In GNU Emacs 20.7.2 (i386-debian-linux-gnu, X toolkit)
 of Fri Apr  5 2002 on cyberhq modified by Debian
configured using `configure  i386-debian-linux-gnu --prefix=/usr --sharedstatedir=/var/lib --libexecdir=/usr/lib --localstatedir=/var/lib --infodir=/usr/share/info --mandir=/usr/share/man --with-pop=yes --with-x=yes --with-x-toolkit=yes'

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:


If I start a subshell in shell mode, and change directories inside
that subshell, the directory tracking code in shell.el is unable to
catch up with the previous state when I exit from the subshell and
return to (the working directory of) the shell where I invoked the
subshell.

I do not have a ready fix for this, but I think it should be possible
to add (a) code to handle "([b?a|k)sh" sort of like pushd; (b) code to
handle "exit" (and maybe "suspend"?) kind of like a mix of popd and
"cd -"; and (c) some sort of mechanics to keep a stack of directory
stacks so that you can simulate the underlying directory stacks
structure in the shells.

As far as I can tell, the modifications should not be major, but I
haven't tried to implement this. Maybe I'll follow up with a patch
eventually.

For the time being, please note this for the record,

/* era */

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