Re: How to get buffer byte length (not number of characters)?

[Eli Zaretskii <eliz@gnu.org>]

> From: Joseph Turner <joseph@ushin.org>
> Cc: emacs-devel@gnu.org, Andreas Schwab <schwab@suse.de>, Adam Porter
>  <adam@alphapapa.net>
> Date: Wed, 21 Aug 2024 02:20:09 -0700
> 
> Let's say I create a textual hyperdrive file using hyperdrive.el, and
> then I upload it by sending its contents via curl to the local HTTP
> server.  What coding system should be used when the file is uploaded?
> 
> Let's say I have a `iso-latin-1'-encoded file "foo.txt" on my local
> filesystem.  I upload this encoded file to my hyperdrive by passing the
> filename to curl, which uploads the bytes with no conversion.  Then I
> open the "foo.txt" hyperdrive file using hyperdrive.el, which receives
> the contents via curl from the local HTTP server.  In the hyperdrive
> file buffer, buffer-file-coding-system should be `iso-latin-1' (right?).

It's what I would expect, yes.  But you can try it yourself, of course
and make sure it is indeed what happens.

> Then, I edit the buffer and save it to the hyperdrive again with
> hyperdrive.el, which this time sends the modified contents over the wire
> to curl.  The uploaded file should be `iso-latin-1'-encoded (right?).

Again, that'd be my expectation.  But it's better to test this
assumption.

> Currently, plz.el always creates the curl subprocess like so:
> 
> (make-process :coding 'binary ...)
> 
> https://git.savannah.gnu.org/cgit/emacs/elpa.git/tree/plz.el?h=externals-release/plz#n519
> 
> Does this DTRT?

It could be TRT if plz.el encodes the buffer text "by hand" before
sending the results to curl and decodes it when it receives text from
curl.  Which I think is what happens there.