Re: master e32c7d2: Change Python eval to send directly instead of using temporary files

[Augusto Stoffel]

On Fri,  3 Sep 2021 at 19:04, Stefan Monnier <monnier@iro.umontreal.ca> wrote:

>>     Change Python eval to send directly instead of using temporary files
>
> FWIW, sending large amounts of text via pty can be troublesome (some
> OSes have been known to insert additional control chars every 256
> bytes, or to do weird things after 4096 bytes leading the send to never
> complete, ...), which is why it's very common for comint modes to send
> regions of text via temp files.
>
>
>         Stefan

Okay, the 4096 bytes limit indeed exists in IPython (but not in the
standard Python interpreters, apparently).

I've attached a patch that reverts to using temporary files for
sufficiently long strings (would this magic 4096 ever require
customization?).  The patch also solves bug#32042, which is mostly
unrelated.

I would like pass text inline as much as possible because the
back-and-forth of temp files is pretty slow over Tramp, which makes the
Python shell rather annoying to use.

As to some OSes inserting additional control characters every 256 bytes,
I've never encountered this, but it seems a rather tricky problem to
work around.  Before this commit, the "plumbing code" sent to the
interpreter could already be above 256 bytes (e.g., if the generated
temp file names are modestly long).  Inserting newline characters at
strategic places would print random prompt strings, and therefore also
introduce complications.

0001-Fixes-for-python-shell-send-string-and-python-shell-.patch
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