[PATCH 2/2] Make parsing of References and In-Reply-To header less error prone

[David Bremner]

Michal Sojka <sojkam1 at fel.cvut.cz> writes:

> According to RFC2822 References and In-Reply-To headers are supposed
> to contain one or more Message-IDs, however older RFC822 allowed
> almost any content. When both References and In-Reply-To headers ends
> with something else that a Message-ID (see e.g. [1]), the thread
> structure presented by notmuch is incorrect. The reason is that
> notmuch treats this case as if the email contained no "replyto"
> information (see _notmuch_database_link_message_to_parents).
>
> This patch changes the parse_references() function to return the last
> valid Message-ID encountered rather than NULL resulting from the last
> hunk of text not being the Message-ID.

This series looks OK to me.  It does touch something pretty fundamental,
so I'd appreciate a second set of eyes on it.

d