ob-shell sessions will send final echo '...' as input key sequence when previous command reads input interactively (was: [Need Help] Error to evaluate "mpv" command in inline src block)

[Ihor Radchenko <yantar92@posteo.net>]

"Christopher M. Miles" <numbchild@gmail.com> writes:

>> So, it looks to me like mpv is somehow trying to interpret "echo" commands the
>> ob-shell is sending after "mpv ...." is executed:
> ...
> Don't know ob-shell which part did your said "echo" commands. I don't
> know where to dig this issue. Hope you can help. Thanks for your
> reproducing problem and dive in.

The underlying issue lies within how comint works + the fact that mpv
reads key input from terminal.

Try the following:

1. emacs -Q
2. M-x shell
3. cd /path/to/your/video <RET>
4. Copy the following into kill ring
-----
mpv "枕刀歌/《枕刀歌》SE05 江海阔 歌谣哼唱.mp4"
m_
-----
5. (in the shell buffer): C-y <RET>
6. Observe mpv playing no sound and video
7. Press m_ to restore video and sound.

I am not sure if we can do much about this though.
We run async shell commands in sessions using

(insert (format ob-shell-async-indicator "start" uuid))
(comint-send-input nil t)
(insert (org-trim body))
(comint-send-input nil t)
(insert (format ob-shell-async-indicator "end" uuid))
(comint-send-input nil t)

which sends

"echo '....'
<your command>
echo '...'"

to comint terminal session.

The last echo '...' in this case is interpreted as key input by mpv -
symbol by symbol.

The only way I know how to work around this is a giant one-liner like
echo '....'; <your command>; echo '...'

However, (1) ";" may not work in some shells; (2) <your command> may
contain multiple lines, leading to the same issue.

Matt, maybe you have some ideas about this edge case?

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
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