[PATCH] Re: introducing xattrMaildir: a Maildir repository where message files have all IMAP flags in an extended attribute

[Erik Quaeghebeur]

>> First of all, I must stress that this patch cannot work without my
>> earlier one “Let OfflineIMAP sync all flags between IMAP servers, not
>> just Maildir-compatible flags”, which is far more invasive, but—I
>> think—also useful to a much wider audience; formulated differently: I
>> think it corrects a historically understandable but wrong design choice
>> and is the more important of the two, needing close scrutiny.
>
> Could you elaborate about this "wrong design choice", please? I don't see what
> you're talking about and how you enhance it.

Consider a message on IMAP server A with IMAP tags '\\Seen' and 
'Custom'. Consider an IMAP server B and a Maildir repository C. Call D 
OfflineIMAP's internal representation (the 'flags' variable).

After synchronization of B and C with A, we have:

* Before my first patch:

	A: (\Seen Custom)
	B: (\Seen)
	C: S
	D: \set(['S'])

* After my first patch:

	A: (\Seen Custom)
	B: (\Seen Custom)
	C: S
	D: \set(['\\Seen', 'Custom'])

* After my second patch, letting C be an xattrMaildir:

	A: (\Seen Custom)
	B: (\Seen Custom)
	C: S (in filename info field)  and
	   "\\Seen Custom" (in user.org.offlineimap extended attribute)
	D: \set(['\\Seen', 'Custom'])