Stop Enigmail trashing layout of pre-formatted quoted text, when signing outgoing mail

[Keith Marshall]

I'm on LinuxMint Debian Edition 1, and upgrading to LMDE2 isn't a convenient option right now. Thunderbird is v38.4.0, (and says it is up to date); Enigmail is v1.9.7, using /usr/bin/gpg2

When posting signed-only plain text to a mailing list, (which frowns on HTML postings), Enigmail utterly destroys the layout of pre-formatted text, when it appears in quoted context. For example, Thunderbird's composition window shows:–

On 17/04/18 11:38, Keith Marshall wrote:
> A possibly more robust implementation of _fseeki64(), suitable for use
> on any Windows version prior to Vista, may be:
>
> __CRT_ALIAS __int64 _fseeki64
> ( FILE *__file, __int64 __pos, int __whence )
> {
>   fseek( __file, 0, SEEK_CUR );
>   return _lseeki64( _fileno(__file), __pos, __whence );
> }

but after processing by Enigmail, to add my GPG signature, the list receives this hideously deformed, and barely comprehensible (to humans) rubbish:–

On 17/04/18 11:38, Keith Marshall wrote:
> A possibly more robust implementation of _fseeki64(), suitable for
> use on any Windows version prior to Vista, may be:
>
> __CRT_ALIAS __int64 _fseeki64 ( FILE *__file, __int64 __pos, int
> __whence ) { fseek( __file, 0, SEEK_CUR ); return _lseeki64(
> _fileno(__file), __pos, __whence ); }

FWIW, the same C-language code, laid out intelligibly within the (unquoted) body of a message, survives processing by Enigmail, unscathed. How do I stop Enigmail trashing layout of pre-formatted text, such as C-language source, when it appears within quoted context? I can't see anything apparently related, within the configuration settings, and Google doesn't seem to be my friend, on this occasion.

[Patrick Brunschwig]

The problem is that inline-PGP is not suitable for such messages. If you don't rewrap the message before the signature is made, then Thunderbird will rewrap the message, and the signature is destroyed.

To avoid this, I'd recommend you use PGP/MIME instead of inline-PGP, which won't change the message in any way.

Alternatively, you can disable rewrapping in Thunderbird entirely by setting the wrap length to 0:
Open the Thunderbird preferences > Advanced Tab > Config editor and change the following setting to 0: mailnews.wraplength

[Keith Marshall]

Thanks, Patrick

The problem is that inline-PGP is not suitable for such messages. If you don't rewrap the message before the signature is made, then Thunderbird will rewrap the message, and the signature is destroyed.

To avoid this, I'd recommend you use PGP/MIME instead of inline-PGP, which won't change the message in any way.

At one time, the list in question lived on SourceForge, and use of PGP/MIME was causing some other problem, (which I can't recall now), so I deselected it. The list has now been moved to OSDN.net, so it may be worth revisiting this.

Alternatively, you can disable rewrapping in Thunderbird entirely by setting the wrap length to 0: Open the Thunderbird preferences > Advanced Tab > Config editor and change the following setting to 0: mailnews.wraplength

That may create other problems. I find Thunderbird's text wrapping to be utterly disgusting anyway ... I want my messages wrapped at a hard right margin of 72 characters, and it's damned annoying that Thunderbird doesn't preserve the layout I see in the composition window, if I miss insertion of a hard line break on every line, without some non-default wrap settings.

[Keith Marshall]

To avoid this, I'd recommend you use PGP/MIME instead of inline-PGP, which won't change the message in any way.

At one time, the list in question lived on SourceForge, and use of PGP/MIME was causing some other problem, (which I can't recall now), so I deselected it.

If memory serves, the issue with SourceForge was that their mailman servers were rewriting PGP/MIME signed messages, and adding content in a manner which invalidated the signature.

The list has now been moved to OSDN.net, so it may be worth revisiting this.

There doesn't seem to be any such problem with OSDN.net handling of PGP/MIME, so this looks like a good solution. Thanks for your help.