Bug when jumping to group in empty topic?

Bug when jumping to group in empty topic?

[Emerick Rogul]

I'm using the latest gnus from CVS and I have the following in my
.gnus.el:

(setq gnus-topic-display-empty-topics nil)

When I use 'j' in the group buffer to jump to a group that's in an
empty topic (and therefore not currently shown in my group buffer),
the new group and all of its parent topics are displayed at the bottom
of my Group buffer under the wrong topic.

For instance, before hitting 'j', my Group buffer looks like this:

  [ archives -- 0 ]
    [ current -- 0 ]
       [5]    0: nnfolder+archive:sent-mail.2003.gz
  [ e-mail -- 0 ]
    [ personal -- 0 ]
       [1]    0: nnml:inbox
  [ news ]
    ...

After hitting 'j' to jump to nnfolder+archive:sent-mail.2002.gz, my
Group buffer looks like this:

  [ archives -- 0 ]
    [ current -- 0 ]
       [5]    0: nnfolder+archive:sent-mail.2003.gz
  [ e-mail -- 0 ]
    [ personal -- 0 ]
       [1]    0: nnml:inbox
  [ news ]
    [ old -- 0 ]
       [5]    0: nnfolder+archive:sent-mail.2002.gz

This looks wrong; I would have expected the topic "old" (and its
group) to appear under the "archives" topic (this is how I have my
topic layout defined).  Is this a misunderstanding on my part or is
there a bug in gnus' behavior?

-Emerick
-- 
-------------------------------------------------------------------------
Emerick Rogul             /\/     "how young are you, how old am i?
emerick@cs.bu.edu         /\/      let's count the rings around my eyes."
------------------------------------------------- 'i will dare', the mats

Re: Bug when jumping to group in empty topic?

[Lars Magne Ingebrigtsen]

Emerick Rogul <emerick@cs.bu.edu> writes:

> When I use 'j' in the group buffer to jump to a group that's in an
> empty topic (and therefore not currently shown in my group buffer),
> the new group and all of its parent topics are displayed at the bottom
> of my Group buffer under the wrong topic.

I'm unable to reproduce this -- when I jump to a group in an
undisplayed topic, the topic inserted in the right place.  There's
probably some subtlety in `gnus-topic-goto-missing-topic' where it
puts point at the wrong place somewhere.  Try edebug-defun on that
function and eval `(gnus-topic-goto-missing-topic "old")'.

-- 
(domestic pets only, the antidote for overdose, milk.)
   larsi@gnus.org * Lars Magne Ingebrigtsen

Re: Bug when jumping to group in empty topic?

[Emerick Rogul]

Lars Magne Ingebrigtsen writes:

> I'm unable to reproduce this -- when I jump to a group in an
> undisplayed topic, the topic inserted in the right place.  There's
> probably some subtlety in `gnus-topic-goto-missing-topic' where it
> puts point at the wrong place somewhere.  Try edebug-defun on that
> function and eval `(gnus-topic-goto-missing-topic "old")'.

I just noticed that it also seems to be affected by the fact that I
have the following in my .gnus.el:

;; always display these groups in the group buffer.
(setq gnus-permanently-visible-groups "^nn\\(dir\\|doc\\|folder\\)")

When I comment out that line, gnus inserts the topic in the correct
place when I hit 'j'.

So the way to reproduce this seems to be:

1) Set gnus-permanently-visible-groups as shown above.
2) Set gnus-display-empty-topics to nil.
3) 'j' to a hidden group (the group probably needs to use one of the
backends specified in gnus-permanently-visible-groups - I use an
nnfolder group).

Does that reproduce the problem for you?

-Emerick
-- 
-------------------------------------------------------------------------
Emerick Rogul             /\/     "how young are you, how old am i?
emerick@cs.bu.edu         /\/      let's count the rings around my eyes."
------------------------------------------------- 'i will dare', the mats

Re: Bug when jumping to group in empty topic?

[Lars Magne Ingebrigtsen]

Emerick Rogul <emerick@cs.bu.edu> writes:

> I just noticed that it also seems to be affected by the fact that I
> have the following in my .gnus.el:
>
> ;; always display these groups in the group buffer.
> (setq gnus-permanently-visible-groups "^nn\\(dir\\|doc\\|folder\\)")
>
> When I comment out that line, gnus inserts the topic in the correct
> place when I hit 'j'.

But if these groups are permanently visible, surely they'll be, er,
permanently visible.  :-)  So is the real bug here that these groups
that are supposed to be in the group buffer all the time aren't
there? 

-- 
(domestic pets only, the antidote for overdose, milk.)
   larsi@gnus.org * Lars Magne Ingebrigtsen

Re: Bug when jumping to group in empty topic?

[Emerick Rogul]

Lars Magne Ingebrigtsen writes:

> But if these groups are permanently visible, surely they'll be, er,
> permanently visible.  :-) So is the real bug here that these groups
> that are supposed to be in the group buffer all the time aren't
> there?

This is getting confusing, so let me draw some pictures :-)

Here's how my summary buffer is logically laid out (note that I keep
nnfolder groups permanently visible):

[ Gnus -- 0 ]
  [ archives -- 0 ]
    [ current -- 0 ]
       [5]    0: nnfolder+archive:sent-mail.2003.gz
       [5]    0: nnfolder+archive:sent-news.2003.gz
    [ old -- 0 ]
      [ 2002 -- 0 ]
         [5]    0: nnfolder+archive:sent-mail.2002.gz
         [5]    0: nnfolder+archive:sent-news.2002.gz
  [ news -- 0 ]
     [5]    *: nntp+quimby.gnus.org:gnus.ding

However, I usually leave both the "2002" topic and the "old" topic
unexpanded, so this is how that looks:

[ Gnus -- 0 ]
  [ archives -- 0 ]
    [ current -- 0 ]
       [5]    0: nnfolder+archive:sent-mail.2003.gz
       [5]    0: nnfolder+archive:sent-news.2003.gz
    [ old -- 0 ]...
  [ news -- 0 ]
     [5]    *: nntp+quimby.gnus.org:gnus.ding

In addition, I have gnus-topic-display-empty-topics set to nil, so the
following is what I actually see in my Summary buffer ("old" is
hidden, since its considered empty):

[ Gnus -- 0 ]
  [ archives -- 0 ]
    [ current -- 0 ]
       [5]    0: nnfolder+archive:sent-mail.2003.gz
       [5]    0: nnfolder+archive:sent-news.2003.gz
  [ news -- 0 ]
     [5]    *: nntp+quimby.gnus.org:gnus.ding

In this scenario, if my cursor is all the way at the bottom of the
Summary buffer and I hit 'j' to jump to the
nnfolder+archive:sent-mail.2002.gz group, the group and its containing
topics are shown in the wrong place, like this:

[ Gnus -- 0 ]
  [ archives -- 0 ]
    [ current -- 0 ]
       [5]    0: nnfolder+archive:sent-mail.2003.gz
       [5]    0: nnfolder+archive:sent-news.2003.gz
  [ news -- 0 ]
     [5]    *: nntp+quimby.gnus.org:gnus.ding
    [ old -- 0 ]
      [ 2002 -- 0 ]
         [5]    0: nnfolder+archive:sent-mail.2002.gz

I'd expect the "old" topic to show up under "archives", not under
"news".  I know this is probably a really bizarre edge-case, but the
behavior still seems pretty weird... :-)

I hope this makes more sense now, sorry it's so long-winded!

-Emerick
-- 
-------------------------------------------------------------------------
Emerick Rogul             /\/     "how young are you, how old am i?
emerick@cs.bu.edu         /\/      let's count the rings around my eyes."
------------------------------------------------- 'i will dare', the mats

Re: Bug when jumping to group in empty topic?

[Lars Magne Ingebrigtsen]

Emerick Rogul <emerick@cs.bu.edu> writes:

> I'd expect the "old" topic to show up under "archives", not under
> "news".  I know this is probably a really bizarre edge-case, but the
> behavior still seems pretty weird... :-)

It's pretty difficult to set up a similar setup myself, so could you
try debugging this?  I would guess that the problem is in
`gnus-topic-goto-missing-topic'.  Try evaling

  M-: (gnus-topic-goto-missing-topic "old")

and see what happens.  If it does the wrong thing, try edebugging
that function and see what it does wrong.

-- 
(domestic pets only, the antidote for overdose, milk.)
   larsi@gnus.org * Lars Magne Ingebrigtsen

Re: Bug when jumping to group in empty topic?

[Emerick Rogul]

Lars Magne Ingebrigtsen writes:

> It's pretty difficult to set up a similar setup myself, so could you
> try debugging this?  I would guess that the problem is in
> `gnus-topic-goto-missing-topic'.  Try evaling

>   M-: (gnus-topic-goto-missing-topic "old")

> and see what happens.  If it does the wrong thing, try edebugging
> that function and see what it does wrong.

Evaling (gnus-topic-goto-missing-topic "old") doesn't do anything in
my setup, which is definitely wrong.  I debugged into that function
and I think the problem is with the following snippet of code:

  (if tp
      (gnus-topic-forward-topic 1)
     (gnus-topic-goto-missing-topic (caadr top)))

When Gnus calls (gnus-topic-forward-topic 1) to move to my "old"
topic, because that topic is currently hidden, nothing happens (point
seems to stay where it currently is).  So the end result is that the
"old" topic is displayed at the bottom of my Group buffer, which is
incorrect given my topic layout.

I think the way to fix this is to make gnus-topic-forward-topic smart
enough to display hidden topics when necessary.  Either that, or we
need to call some code to display the hidden topic(s) _before_ calling
gnus-topic-forward-topic -- actually, that seems like the better way
to do this.  I'm not sure I know enough about Gnus internals to know
what to change, though.  Any thoughts?

-Emerick
-- 
-------------------------------------------------------------------------
Emerick Rogul             /\/     "how young are you, how old am i?
emerick@cs.bu.edu         /\/      let's count the rings around my eyes."
------------------------------------------------- 'i will dare', the mats

Re: Bug when jumping to group in empty topic?

[Lars Magne Ingebrigtsen]

Emerick Rogul <emerick@cs.bu.edu> writes:

>   (if tp
>       (gnus-topic-forward-topic 1)
>      (gnus-topic-goto-missing-topic (caadr top)))

Hm.  I'm unable to reproduce the bug, but I've just replaced
`(gnus-topic-forward-topic 1)' with `(forward-line 1)' in that
function.  Does that fix the problem for you?

-- 
(domestic pets only, the antidote for overdose, milk.)
   larsi@gnus.org * Lars Magne Ingebrigtsen