bug#42160: Issue with Man-kill and background process.

[Eli Zaretskii <eliz@gnu.org>]

Ping!

> Date: Fri, 03 Jul 2020 11:02:08 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 42160@debbugs.gnu.org
> 
> > Date: Thu, 2 Jul 2020 04:23:09 +0200
> > From: Ergus via "Bug reports for GNU Emacs,
> >  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> > 
> > When using man with big manuals (like gcc). There is an error when
> > trying to quit with k just after opening the manual.
> > This seems to be related with the formating process that is running in
> > the background.
> > 
> > To reproduce the issue:
> > 
> > emacs -Q
> > M-x toggle-debug-on-error RET
> > M-x man RET
> > gcc RET
> > k
> > 
> > And I get this error message:
> > 
> > Debugger entered--Lisp error: (wrong-type-argument stringp nil)
> >   Man-bgproc-filter(#<process man> "nt, there is no need to use address spaces like \"_...")
> 
> Thanks.  Does the patch below fix this?
> 
> diff --git a/lisp/man.el b/lisp/man.el
> index 5278a1a..bc8fd45 100644
> --- a/lisp/man.el
> +++ b/lisp/man.el
> @@ -1392,7 +1392,7 @@ Man-bgproc-filter
>  command is run.  Second argument STRING is the entire string of output."
>    (save-excursion
>      (let ((Man-buffer (process-buffer process)))
> -      (if (null (buffer-name Man-buffer)) ;; deleted buffer
> +      (if (not (buffer-live-p Man-buffer)) ;; deleted buffer
>  	  (set-process-buffer process nil)
>  
>  	(with-current-buffer Man-buffer
> @@ -1426,7 +1426,7 @@ Man-bgproc-sentinel
>  	(delete-buff nil)
>  	message)
>  
> -    (if (null (buffer-name Man-buffer)) ;; deleted buffer
> +    (if (not (buffer-live-p Man-buffer)) ;; deleted buffer
>  	(or (stringp process)
>  	    (set-process-buffer process nil))
>  
> 
> 
> 
>