[Users] [Bug 4217] Claws Mail 3.17.3 changes content of an attachment on sending message

[Paul Steyn]

On Thu, 6 Jun 2019 19:38:52 +0200
Johan Vromans <jvromans at squirrel.nl> wrote:

> On Thu, 06 Jun 2019 17:16:45 +0000, noreply at thewildbeast.co.uk wrote:
> 
> > https://www.thewildbeast.co.uk/claws-mail/bugzilla/show_bug.cgi?id=4217
> > 
> > --- Comment #6 from Paul <paul at claws-mail.org> ---
> > (In reply to comment #5)
> > > Sorry. Which lines? I **attached** a file not insert. How a
> > > attachment could be changed at all?  
> > 
> > Attachments are encoded. They are also wrapped so they do not
> > exceed the maximum allowed line length (998 bytes) This is a
> > standard specified in RFC 2822. See
> > https://tools.ietf.org/html/rfc2822
> 
> One may expect that upon receipt the attachment is unwrapped and
> decoded, producing a bit-for-bit identical copy of the original file.

I would most definitely expect that received attachments are unwrapped
and decoded to a bit-identical copy of the original. What if the file
is binary, where line wrapping would break the file, and not html,
where the line wrapping might not matter?

Even if the file is not binary (or source code, which might
conceivably also break if lines are wrapped), I would expect that I
could do a hash on the file and verify that hash against a hash of the
original, as proof that the file is both uncorrupted by the transfer,
and the intended file and not a mistakenly attached obsolete version,
for example.