bug#35208: 27.0.50; Gnus nndraft error when saving message buffer

bug#35208: 27.0.50; Gnus nndraft error when saving message buffer

[Basil L. Contovounesios]

Trying to save a draft, e.g. as follows:

0. HOME=$(mktemp -d) emacs -Q
1. M-x toggle-debug-on-error RET
2. (setq gnus-select-method '(nnnil)) C-j
3. M-x gnus RET
4. m
5. foo C-x C-s

results in the following error:

--8<---------------cut here---------------start------------->8---
Debugger entered--Lisp error: (wrong-type-argument number-or-marker-p nil)
  nndraft-update-unread-articles()
  run-hooks(after-save-hook)
  basic-save-buffer(t)
  save-buffer(1)
  funcall-interactively(save-buffer 1)
  call-interactively(save-buffer nil nil)
  command-execute(save-buffer)
--8<---------------cut here---------------end--------------->8---

Reevaluating nndraft-update-unread-articles and repeating step (5) gives
the following backtrace:

--8<---------------cut here---------------start------------->8---
Debugger entered--Lisp error: (wrong-type-argument number-or-marker-p nil)
  =(0 nil)
  (if (= 0 (gnus-group-group-unread)) (progn (delete-region (point-at-bol) (progn (forward-line 1) (point)))))
  (if (and gnus-permanently-visible-groups (string-match gnus-permanently-visible-groups group)) nil (gnus-group-goto-group group) (if (= 0 (gnus-group-group-unread)) (progn (delete-region (point-at-bol) (progn (forward-line 1) (point))))))
  (while --dolist-tail-- (setq group (car --dolist-tail--)) (if (and gnus-permanently-visible-groups (string-match gnus-permanently-visible-groups group)) nil (gnus-group-goto-group group) (if (= 0 (gnus-group-group-unread)) (progn (delete-region (point-at-bol) (progn (forward-line 1) (point)))))) (setq --dolist-tail-- (cdr --dolist-tail--)))
  (let ((--dolist-tail-- groups) group) (while --dolist-tail-- (setq group (car --dolist-tail--)) (if (and gnus-permanently-visible-groups (string-match gnus-permanently-visible-groups group)) nil (gnus-group-goto-group group) (if (= 0 (gnus-group-group-unread)) (progn (delete-region (point-at-bol) (progn (forward-line 1) (point)))))) (setq --dolist-tail-- (cdr --dolist-tail--))))
  (save-excursion (let ((--dolist-tail-- groups) group) (while --dolist-tail-- (setq group (car --dolist-tail--)) (if (and gnus-permanently-visible-groups (string-match gnus-permanently-visible-groups group)) nil (gnus-group-goto-group group) (if (= 0 (gnus-group-group-unread)) (progn (delete-region (point-at-bol) (progn ... ...))))) (setq --dolist-tail-- (cdr --dolist-tail--)))))
  (let* ((groups (mapcar #'(lambda (elem) (gnus-group-prefixed-name (car elem) (list ... ""))) (nnmail-get-active))) (gnus-group-marked (copy-sequence groups)) (gnus-get-new-news-hook nil) (inhibit-read-only t)) (gnus-group-get-new-news-this-group nil t) (save-excursion (let ((--dolist-tail-- groups) group) (while --dolist-tail-- (setq group (car --dolist-tail--)) (if (and gnus-permanently-visible-groups (string-match gnus-permanently-visible-groups group)) nil (gnus-group-goto-group group) (if (= 0 (gnus-group-group-unread)) (progn (delete-region ... ...)))) (setq --dolist-tail-- (cdr --dolist-tail--))))))
  (save-current-buffer (set-buffer gnus-group-buffer) (let* ((groups (mapcar #'(lambda (elem) (gnus-group-prefixed-name ... ...)) (nnmail-get-active))) (gnus-group-marked (copy-sequence groups)) (gnus-get-new-news-hook nil) (inhibit-read-only t)) (gnus-group-get-new-news-this-group nil t) (save-excursion (let ((--dolist-tail-- groups) group) (while --dolist-tail-- (setq group (car --dolist-tail--)) (if (and gnus-permanently-visible-groups (string-match gnus-permanently-visible-groups group)) nil (gnus-group-goto-group group) (if (= 0 ...) (progn ...))) (setq --dolist-tail-- (cdr --dolist-tail--)))))))
  nndraft-update-unread-articles()
  run-hooks(after-save-hook)
  basic-save-buffer(t)
  save-buffer(1)
  funcall-interactively(save-buffer 1)
  call-interactively(save-buffer nil nil)
  command-execute(save-buffer)
--8<---------------cut here---------------end--------------->8---

I'm temporarily working around this by
changing (zerop (gnus-group-group-unread))
to (eq 0 (gnus-group-group-unread)),
but a larger problem seems to be at play.

Any tips?  Thanks,

-- 
Basil

Gnus v5.13
In GNU Emacs 27.0.50 (build 1, x86_64-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2019-04-09 built on thunk
Repository revision: 44b306d3510e54432b76724583ea9405f1c90686
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12003000
System Description: Debian GNU/Linux buster/sid

Configured using:
 'configure 'CC=ccache gcc' 'CFLAGS=-O2 -march=native' --config-cache
 --prefix=/home/blc/.local --with-mailutils --with-x-toolkit=lucid
 --with-modules --with-file-notification=yes --with-x'

Configured features:
XAW3D XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS
GLIB NOTIFY INOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT
LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS LUCID X11 XDBE XIM MODULES THREADS
LIBSYSTEMD JSON PDUMPER LCMS2 GMP

bug#35208: 27.0.50; Gnus nndraft error when saving message buffer

[Katsumi Yamaoka]

On Tue, 09 Apr 2019 14:46:20 +0100, Basil L. Contovounesios wrote:
> Trying to save a draft, e.g. as follows:

> 0. HOME=$(mktemp -d) emacs -Q
> 1. M-x toggle-debug-on-error RET
> 2. (setq gnus-select-method '(nnnil)) C-j
> 3. M-x gnus RET
> 4. m
> 5. foo C-x C-s

> results in the following error:

The message is saved with no error, hmmm.  I did

mv .emacs dot-emacs
mv .newsrc dot-newsrc
mv .newsrc.eld dot-newsrc.eld
mv .gnus.el dot-gnus.el
rm .*~

and the recipe with the latest Emacs master.

Regards,

bug#35208: 27.0.50; Gnus nndraft error when saving message buffer

[Basil L. Contovounesios]

Katsumi Yamaoka <yamaoka@jpl.org> writes:

> On Tue, 09 Apr 2019 14:46:20 +0100, Basil L. Contovounesios wrote:
>> Trying to save a draft, e.g. as follows:
>
>> 0. HOME=$(mktemp -d) emacs -Q
>> 1. M-x toggle-debug-on-error RET
>> 2. (setq gnus-select-method '(nnnil)) C-j
>> 3. M-x gnus RET
>> 4. m
>> 5. foo C-x C-s
>
>> results in the following error:
>
> The message is saved with no error, hmmm.  I did
>
> mv .emacs dot-emacs
> mv .newsrc dot-newsrc
> mv .newsrc.eld dot-newsrc.eld
> mv .gnus.el dot-gnus.el
> rm .*~
>
> and the recipe with the latest Emacs master.

Hmm, that's odd.  I can reproduce the error 100% of the time.
I even tried a clean Emacs checkout on a clean OS install:

0. Install Debian Testing in a VirtualBox VM.
1. apt-get build-dep emacs-lucid
2. git clone https://git.savannah.gnu.org/git/emacs.git
3. cd emacs
4. ./autogen.sh all && ./configure && make
5. ./src/emacs -Q
6. Repeat steps 1-5 from my OP.

I include the details of this Emacs build after my signature.

Another thing I noticed, which I don't remember seeing before:

0. HOME=$(mktemp -d) emacs -Q
1. (setq gnus-select-method '(nnnil)) C-j
2. M-x gnus RET
3. m
4. C-x 4 C-o RET
5. foo C-x C-s

The *Group* buffer now has the following contents:

       1: nndraft:drafts
 K#    0: nndraft:queue

where the text properties at bol of the first group are:

  cursor-sensor-functions (gnus-tool-bar-update)
  face                 gnus-group-mail-1
  gnus-group           "nndraft:drafts"
  gnus-indentation     ""
  gnus-level           1
  gnus-marked          32
  gnus-unread          1

and those at bol of the second group are:

  cursor-sensor-functions (gnus-tool-bar-update)
  face                 gnus-group-news-low-empty
  gnus-group           "nndraft:queue"
  gnus-indentation     ""
  gnus-level           9
  gnus-marked          32
  gnus-unread          0

In Emacs 26, the second group nndraft:queue doesn't appear after saving
the *unsent mail* buffer.  I suspect this seemingly unexpected group has
something to do with nndraft-update-unread-articles choking.

Thanks,

-- 
Basil

In GNU Emacs 27.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.5)
 of 2019-04-10 built on test
Repository revision: 0cef057b02b088ded8b46e3453ac0d891888423a
Repository branch: master
System Description: Debian GNU/Linux buster/sid

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS GLIB
NOTIFY INOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF
XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM THREADS LIBSYSTEMD
PDUMPER LCMS2 GMP

Important settings:
  value of $LANG: en_IE.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Message

Minor modes in effect:
  gnus-message-citation-mode: t
  mml-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  auto-fill-function: message-do-auto-fill
  transient-mark-mode: t
  abbrev-mode: t

Load-path shadows:
None found.

bug#35208: 27.0.50; Gnus nndraft error when saving message buffer

[Katsumi Yamaoka]

On Wed, 10 Apr 2019 18:24:02 +0100, Basil L. Contovounesios wrote:
> Katsumi Yamaoka <yamaoka@jpl.org> writes:
>> The message is saved with no error, hmmm.
[...]
> Hmm, that's odd.  I can reproduce the error 100% of the time.

Oh, I could 100% reproduce this issue.  Maybe the cause of
the failure was I did it in the real home directory instead of
the pseudo home.  Probably Gnus loaded something from ~/News .
Sorry.

Me culprit.  The cause is that `nndraft-update-unread-articles'
fails to go to the nndraft:queue group (in order to delete the
group line if the group has no unread article).  nndraft:queue
and its directory are created when Gnus launches, and it is
registered into `gnus-active-hashtb' but not `gnus-newsrc-hashtb'.
So, `gnus-group-goto-group', that I recently changed so as to
use `gnus-newsrc-hashtb' instead of `gnus-active-hashtb', fails
to find the nndraft:queue group.

I've pushed the fix.  Thank you for pointing this out.

Regards,

bug#35208: 27.0.50; Gnus nndraft error when saving message buffer

[Basil L. Contovounesios]

Katsumi Yamaoka <yamaoka@jpl.org> writes:

> Me culprit.  The cause is that `nndraft-update-unread-articles'
> fails to go to the nndraft:queue group (in order to delete the
> group line if the group has no unread article).  nndraft:queue
> and its directory are created when Gnus launches, and it is
> registered into `gnus-active-hashtb' but not `gnus-newsrc-hashtb'.
> So, `gnus-group-goto-group', that I recently changed so as to
> use `gnus-newsrc-hashtb' instead of `gnus-active-hashtb', fails
> to find the nndraft:queue group.
>
> I've pushed the fix.  Thank you for pointing this out.

I can confirm your patch fixed the problem.
Thanks for the quick fix and explanation!

-- 
Basil