bug#21043: [PATCH] nnimap.el: make capability parsing more robust.

bug#21043: [PATCH] nnimap.el: make capability parsing more robust.

[Nikolaus Rath]

Package: gnus
Tags: patch

Hello,

Currently Gnus relies on the server supplying the capabilities in its
response to the LOGIN command, e.g. like this:

  * CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE
  SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS THREAD=ORDEREDSUBJECT
  MULTIAPPEND URL-PARTIAL CATENATE UNSELECT CHILDREN NAMESPACE UIDPLUS
  LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES
  WITHIN CONTEXT=SEARCH LIST-STATUS SPECIAL-USE BINARY MOVE SEARCH=FUZZY
  QUOTA\r\n
  1 OK Logged in\r\n

However, this assumption breaks if the server doesn't return the
capabilities automatically, or if he returns them as part of the OK
response, e.g.:

   160 OK [CAPABILITY IMAP4rev1 LITERAL+ ID ENABLE ACL RIGHTS=kxten
   QUOTA MAILBOX-REFERRALS NAMESPACE UIDPLUS NO_ATOMIC_RENAME UNSELECT
   CHILDREN MULTIAPPEND BINARY CATENATE CONDSTORE ESEARCH SEARCH=FUZZY
   SORT SORT=MODSEQ SORT=DISPLAY SORT=UID THREAD=ORDEREDSUBJECT
   THREAD=REFERENCES ANNOTATEMORE ANNOTATE-EXPERIMENT-1 METADATA
   LIST-EXTENDED LIST-STATUS LIST-MYRIGHTS LIST-METADATA WITHIN QRESYNC
   SCAN XLIST XMOVE MOVE SPECIAL-USE CREATE-SPECIAL-USE DIGEST=SHA1
   X-REPLICATION LOGINDISABLED XCONVERSATIONS COMPRESS=DEFLATE
   X-QUOTA=STORAGE X-QUOTA=MESSAGE X-QUOTA=X-ANNOTATION-STORAGE
   X-QUOTA=X-NUM-FOLDERS IDLE] User logged in
   SESSIONID=<sloti32d1t18-237747-1436749914-1-18339819756817078727>\r\n


Currently, in this situation Gnus just keeps re-using the pre-LOGIN
capabilities (and thus does not take advantage of any additional
features).

The attached patch fixes this issue by explicitly asking the server for
its capabilities after login.


Thanks for considering,
-Nikolaus


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Re: bug#21043: [PATCH] nnimap.el: make capability parsing more robust.

[Eric Abrahamsen]

Nikolaus Rath <Nikolaus@rath.org> writes:

> Package: gnus
> Tags: patch

There was no patch!

Re: bug#21043: [PATCH] nnimap.el: make capability parsing more robust.

[Nikolaus Rath]

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On Jul 13 2015, Eric Abrahamsen <eric@ericabrahamsen.net> wrote:
> Nikolaus Rath <Nikolaus@rath.org> writes:
>
>> Package: gnus
>> Tags: patch
>
> There was no patch!

Oops. Here it is.

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[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: 0001-nnimap.el-make-capability-parsing-more-robust.patch --]
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From 241812047dedb1ba7d362c4211a06bf506d37237 Mon Sep 17 00:00:00 2001
From: Nikolaus Rath <Nikolaus@rath.org>
Date: Sun, 12 Jul 2015 18:42:48 -0700
Subject: [PATCH] nnimap.el: make capability parsing more robust.

* lisp/nnimap.el (nnimap-open-connection-1): explicitly ask server for
capabilities instead of relying on LOGIN response.
---
 lisp/ChangeLog | 5 +++++
 lisp/nnimap.el | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index d8ab42e..83ac4c4 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,10 @@
 2015-07-12 Nikolaus Rath <Nikolaus@rath.org>
 
+	* nnimap.el (nnimap-open-connection-1): explicitly ask server for
+	capabilities instead of relying on LOGIN response.
+
+2015-07-12 Nikolaus Rath <Nikolaus@rath.org>
+
 	* nnimap.el (nnimap-request-group-scan)
 	(nnimap-request-create-group, nnimap-request-delete-group)
 	(nnimap-request-rename-group, nnimap-request-move-article)
diff --git a/lisp/nnimap.el b/lisp/nnimap.el
index d11b3a2..19632ad 100644
--- a/lisp/nnimap.el
+++ b/lisp/nnimap.el
@@ -520,7 +520,7 @@ If non-nil, articles flagged as deleted (using the IMAP
 			(funcall (nth 2 credentials)))
 		      ;; See if CAPABILITY is set as part of login
 		      ;; response.
-		      (dolist (response (cddr login-result))
+		      (dolist (response (cddr (nnimap-command "CAPABILITY")))
 			(when (string= "CAPABILITY" (upcase (car response)))
 			  (setf (nnimap-capabilities nnimap-object)
 				(mapcar #'upcase (cdr response))))))
-- 
2.1.4

Re: bug#21043: [PATCH] nnimap.el: make capability parsing more robust.

[Lars Magne Ingebrigtsen]

Nikolaus Rath <Nikolaus@rath.org> writes:

> -		      (dolist (response (cddr login-result))
> +		      (dolist (response (cddr (nnimap-command "CAPABILITY")))

That'll be an extra round trip when logging in...

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Re: bug#21043: [PATCH] nnimap.el: make capability parsing more robust.

[Nikolaus Rath]

On Jul 13 2015, Lars Magne Ingebrigtsen <larsi@gnus.org> wrote:
> Nikolaus Rath <Nikolaus@rath.org> writes:
>
>> -		      (dolist (response (cddr login-result))
>> +		      (dolist (response (cddr (nnimap-command "CAPABILITY")))
>
> That'll be an extra round trip when logging in...

Yes. But that's not exactly a critical path, is it?


Best,
-Nikolaus

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Re: bug#21043: [PATCH] nnimap.el: make capability parsing more robust.

[Lars Magne Ingebrigtsen]

Nikolaus Rath <Nikolaus@rath.org> writes:

> Subject: [PATCH] nnimap.el: make capability parsing more robust.

[...]

> -		      (dolist (response (cddr login-result))
> +		      (dolist (response (cddr (nnimap-command "CAPABILITY")))

And we've already issued the CAPABILITY command in the
`open-protocol-stream' call, so if the results of that isn't in
`login-results', there's a bug in `open-protocol-stream'.

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   bloggy blog: http://lars.ingebrigtsen.no

Re: bug#21043: [PATCH] nnimap.el: make capability parsing more robust.

[Nikolaus Rath]

On Jul 13 2015, Lars Magne Ingebrigtsen <larsi@gnus.org> wrote:
> Nikolaus Rath <Nikolaus@rath.org> writes:
>
>> Subject: [PATCH] nnimap.el: make capability parsing more robust.
>
> [...]
>
>> -		      (dolist (response (cddr login-result))
>> +		      (dolist (response (cddr (nnimap-command "CAPABILITY")))
>
> And we've already issued the CAPABILITY command in the
> `open-protocol-stream' call, so if the results of that isn't in
> `login-results', there's a bug in `open-protocol-stream'.

No. The results of the CAPABILITY command before login may be different
than after login.

Best,
-Nikolaus

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