This patch adds a new configuration variable, 'stuff_all_quoted'. When set, mutt will space-stuff all non-empty quoted lines in displayed and generated text/plain; format=flowed attachments, as allowed by RFC 2646. That is, quoted lines will appear as "> text" rather than ">text" when displayed and in replies and forwards. This makes the quoting in format=flowed text easier to read and more consistent with the quoting style traditionally used for format=fixed text. When unset, mutt will space-stuff quoted lines only as required by RFC 2646, as it does without the patch.
This patch allows mutt to replace spaces by underscores when attachments are saved. The configuration variable that enables this feature is named attach_sanitize because the behavior it controls is similar to that of the existing mailcap_sanitize variable. To enable this feature, execute the following from the mutt command line or put it in your muttrc.
When 'sigontop' is set, mutt places the signature at the top of forwards and replies, but it doesn't follow the signature with any blank lines to separate it from the text of the message being forwarded or replied to. This patch fixes that problem by adding a blank line following the on-top signature when appropriate.
The patch itself has a bug in that it also follows the signature with a blank line when forwarding attachments and all the parts are actually sent as attachments and not as in-line text. However, this seems like a minor problem and fixing it would require much more extensive changes to the mutt code.
When HAVE_LIBIDN is not defined, the raw_socket_open() function in mutt_socket.c attempts to free a string that was not dynamically allocated. This is a bad thing. This patch fixes that problem by allowing the string to be freed only if HAVE_LIBIDN is defined.