Subject: Re: [RFC PATCH] format-patch: thread as reply to cover letter even with in-reply-to

From: Thomas Rast <[email-masked]>
Date: Mon, 16 Feb 2009 21:34:20 +0100

Jay Soffian wrote:
> I think this change may be okay, but I think to go with it the
> cover-letter and all the patches should have a "References:" header
> with the message-id given by --in-reply-to.

That's a completely separate issue.  I'm only proposing to change
what is formatted as a reply to what, the In-Reply-To and References
formatting is handled by the existing code.  That being said...

> RFC 2822 says:
> 
>    The "In-Reply-To:" and "References:" fields are used when creating a
>    reply to a message.  They hold the message identifier of the original
>    message and the message identifiers of other messages (for example,
>    in the case of a reply to a message which was itself a reply).  The
>    "In-Reply-To:" field may be used to identify the message (or
>    messages) to which the new message is a reply, while the
>    "References:" field may be used to identify a "thread" of
>    conversation.

The References formatting can't satisfy the following requirement, two
paragraphs further down in the RFC,

   The "References:" field will contain the contents of the parent's
   "References:" field (if any) followed by the contents of the parent's
   "Message-ID:" field (if any).

because it doesn't have access to the mail being replied to.  It
merely sets References to the same as In-Reply-To.

(Note that I'm just guessing this from behaviour I can observe, I
haven't actually read the code for that part.)

-- 
Thomas Rast
trast@{inf,student}.ethz.ch