[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
bug#52735: 29.0.50; Gnus hangs while getting new news
From: |
Stephen Berman |
Subject: |
bug#52735: 29.0.50; Gnus hangs while getting new news |
Date: |
Thu, 23 Dec 2021 00:13:38 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (gnu/linux) |
On Wed, 22 Dec 2021 09:54:32 -0800 Eric Abrahamsen <eric@ericabrahamsen.net>
wrote:
On 12/22/21 18:42 PM, Stephen Berman wrote:
>> On Wed, 22 Dec 2021 08:23:35 -0800 Eric Abrahamsen <eric@ericabrahamsen.net>
>> wrote:
>>
>>> Stephen Berman <stephen.berman@gmx.net> writes:
>>>
>>>> The hang appears to happen in nntp-finish-retrieve-group-infos: stepping
>>>> through the code with Edebug, I see an infinite loop here:
>>>>
>>>> (while (and (gnus-buffer-live-p buf)
>>>> (progn
>>>> (goto-char last-point)
>>>> ;; Count replies.
>>>> (while (re-search-forward
>>>> (if nntp-server-list-active-group
>>>> "^[.]"
>>>> "^[0-9]")
>>>> nil t)
>>>> (cl-incf received))
>>>> (setq last-point (point))
>>>> (< received count)))
>>>> (nntp-accept-response))
>>>>
>>>> when the server buffer (e.g. " *server news.gmane.io nntp *nntpd**") is
>>>> empty. Since this code clearly does not expect an empty buffer, the bug
>>>> is presumably making this buffer empty when this code is executed. But
>>>> I haven't managed to figure out how this happens. (I have seen that
>>>> this buffer can become empty in other situations, e.g. on opening an
>>>> article in Gnus, and that doesn't cause any problems.) I've also
>>>> observed that when I wait long enough for the server process to close
>>>> (the buffer then shows "Process nntpd connection broken by remote
>>>> peer"), then there is no hang on typing `g' in the *Group* buffer.
>>>
>>> The only thing I can suggest now is more debugging on
>>> `nntp-finish-retrieve-group-infos', and try to get a backtrace for both
>>> the buggy empty-buffer situation, and the normal, non-empty-buffer
>>> situation. Perhaps comparing the two backtraces will provide a clue as
>>> to how we ended up with an empty buffer?
>>
>> So far, I determined that problem isn't the empty buffer per se, but
>> that it remains empty after (nntp-accept-response) returns, that's why
>> the while-loop keeps looping. I'll try to dig into nntp-accept-response.
>
> This is probably a total red herring, but... look for `copy-to-buffer'
> calls that are pointing at the wrong buffer (ie, the process output is
> supposed to go to nntp-server-buffer, but it goes elsewhere).
I haven't succeeded in following the nntp-accept-response call that
leaves the server buffer empty to any code calling copy-to-buffer. The
pattern I see is that there are two calls of nntp-accept-response in the
while-loop that leave the buffer empty, and on the third iteration,
either the buffer is filled with data, or it remains empty, causing the
hang. I added a counter to the loop and when it reaches 3 a call to
nntp-kill-buffer to kill the server buffer: this results in a bunch of
"Warning - invalid active" messages but doesn't hang. When I then type
`g' in the *Group* buffer, fetching new news successfully completes. So
this just mimics the effect of `C-g' followed by `g' as I reported
above. But I'm no closer to the reason for the hang or how to track it
down. Since no one else seems to be having this problem, that suggests
a problem with my connection to news.gmane.io; is there anything I can
do to investigate that?
Steve Berman