234552 - Thunderbird stops checking for new mail after a while

Status: RESOLVED DUPLICATE of bug 173924

(MailNews Core :: Networking: POP, defect)

Description

[Gregg]

User-Agent:       
Build Identifier: Mozilla Thunderbird 0.5+ (20040212)

If Thunderbird is set to automatically check for mail periodically, it stops
checking after running for some indeterminate amount of time. Manual checks do
not work at this point either.

I tried to figure this one out myself, because it has been present since 0.4,
and nobody else seems to be running into it. A previous bug report (227617) was
filed (and I added a comment), but it was assigned to the "preferences"
component, which seems wrong.

I pulled in the latest source from CVS and built my own debug copy and ran it in
the debugger. When the no-check syndrome begain, I set a breakpoint in
nsPop3Service::RunPopUrl. If I click on "Get New Mail" toolbar button, it hits
this breakpoint, which is good. I then see that it skips the check because the
"serverBusy" flag is set. I guess this flag is used to prevent reentering while
a check is in progress. It appears to remain set indefinitely. Isn't there some
kind of timeout for this?

Other interesting state information is that mPerformingBiff is set to 1, which
suggests that a previous automatic check never completed. There is also a
m_biffState variable which has a value of 2, whatever that means.

The POP state is
m_runningProtocol.mRawPtr.nsPop3Protocol.m_pop3ConData.nextState is
POP3_START_CONNECT. The value next_state_after_response is POP3_FINISH_CONNECT.
The value capability_flags = 1194.

It will take someone with more insight into how this code works than I have to
figure out why this is happening and how to fix it. It seems not particularly
resiliant to server protocol failures.


Reproducible: Always
Steps to Reproduce:
1. Set an automatic POP account check for one minute.
2. Wait an hour or so. This might be accelerated by terminating a dialup
connection, waiting a few minutes, and reestablishing it.
3. Click the "Get New Mail" toolbar button. If the status bar does not indicated
it is checking, then the bug has occurred.

Actual Results:  
Clicking the "Get New Mail" toolbar button has no effect. An email sent from
another computer is not received until I terminate Thunderbird and restart it.


Expected Results:  
The software should retrieve the mail on the next scheduled check.


This was for checking a single Earthlink POP account with a "mindspring.com"
domain. I've noticed that when I run other mail clients to check this server,
they occasionally issue timeout errors attempting to connect, whereas
Thunderbird never does this.

Comment 1

[Gregg]

Additional note: I've also encountered the situation where the automatic check
stops being performed, but manual checks (clicking on "Get Mail") continue to
work. I have not analyzed this case under a debugger, though. I think it always
happens after reestablishing a dial-up connection that has been disconnected for
several hours.

Comment 2

[Calum Mackay]

I see this behaviour on linux/x86 Thunderbird 20040218, against an IMAP server.
I also have check for new mail set. Manual checks do not get it working; I have
to restart (at which point everything is again fine).

I wondered whether it was some interaction with another IMAP client. I'm also
using gnubiif against this IMAP server (for the same INBOX).

Comment 3

[Travis Chase]

*** Bug 234567 has been marked as a duplicate of this bug. ***

Comment 4

[Asa Dotzler [:asa]]

*** This bug has been marked as a duplicate of 227617 ***

Comment 5

[:Gavin Sharp [email: [e-mail]]]

*** This bug has been marked as a duplicate of 173924 ***