bug#39506: patch

[Stefan Monnier]

> In the changelog message of commit d4eb2b7, you claim to "set the
> buffer to unibyte before inserting" but it's not clear where.

The focus of the sentence is on "before": the previous code already set
the buffer to unibyte, but it did it afterwards.

> Then in a later comment, you say "may happen that the handle-buffer is
> multibyte... in which case now is a good time to adjust it, since we
> know ... it should be unibyte."  The revision before that preserves
> the multibyte-p setting, so I do the same in this patch.

As the motivation for your patch, you write:
> In my Gnus experience, the source buffer that mm-shr acts upon can be
> multibyte.

Two questions:
- How does `mm-with-part` relate to `mm-shr`?
- Before deciding whether unibyte or multibyte is the right choice, the
  main question is whether the buffer contains bytes or chars.
  AFAIK `mm-with-part` should only ever handle bytes (otherwise calling
  `mm-decode-content-transfer-encoding` doesn't make much sense).
  Your patch suggests you have a use case where this is not true.
  Can you give more details about this case?
  Maybe a backtrace showing how we got to this particular call to
  `mm-with-part`?


-- Stefan