Re: misbehavior in shell window with ksh

[Eli Zaretskii <eliz@gnu.org>]

> From: Stephen Berman <stephen.berman@gmx.net>
> Cc: mkupfer@alum.berkeley.edu,  emacs-devel@gnu.org
> Date: Tue, 02 May 2017 14:35:44 +0200
> 
> > What if you step into comint-output-filter with Edebug (as you already
> > seem to have a way of doing that), then type 'd' to produce a
> > backtrace?  Does that show who called comint-output-filter?
> 
> Unfortunately not.  FTR: I instrumented comint-output-filter for Edebug
> and started the recipe.  On entering `ksh RET' at the shell prompt,
> Edebug took control and I typed `d' and got this backtrace:
> 
>   comint-output-filter(#<process shell> "steve@rosalinde:/home/steve> ")
> 
> I typed `q' and continued with the recipe, and at `C-x 0' (M-o and M-0
> above were typos) Edebug again took over, and `d' produced this
> backtrace:
> 
>   comint-output-filter(#<process shell> "> ")
> 
> > It could be that it is called by the process-filter mechanism, which
> > is in C.  But what we want to know is where does the 2nd arg of
> > comint-output-filter comes from, and why.
> 
> If you can advise me what to try in gdb, I can do that.

Get Emacs to stop in comint-output-filter using Edebug, then attach
GDB, make sure src/.gdbinit is being source'd by GDB, and type

  (gdb) bt

This should producve both C-level backtrace and Lisp-level backtrace.