bug#57854: 29.0.50; Different exit code in Emacs and terminal for identical process

[Eli Zaretskii]

> From: dalanicolai <dalanicolai@gmail.com>
> Date: Fri, 16 Sep 2022 12:00:09 +0200
> 
> When looking into the `pdftocio` package I find the following piece of code
> 
> ```
>     try:
>         with open_pdf(path_in) as doc:
>             if toc_file.isatty() or print_toc:
>                 # no input from user, switch to output mode and extract the 
> toc
>                 # of pdf
>                 toc = read_toc(doc)
>                 if len(toc) == 0:
>                     print("error: no table of contents found", 
> file=sys.stderr)
>                     sys.exit(1)
> 
>                 if readable:
>                     print(pprint_toc(toc))
>                 else:
>                     print(dump_toc(toc), end="")
>                 sys.exit(0)
> 
>             # an input is given, so switch to input mode
>             toc = parse_toc(toc_file)
>             write_toc(doc, toc)
> ```

Note that the above distinguishes between TTY and non-TTY input, and
call-process works via the non-TTY case, AFAIU.  So maybe what you see
is entirely expected?