Created attachment 31665 [details]
screenshot showing UIDL-requester

+++ This bug was initially created as a clone of Bug #157946 +++

Version:           1.9.10 (openSUSE 11.1)
Prerequisites/Preset:
POP3 account, msgs stay on server, (about 2500 msgs/25Meg on server).
Lots of mails in kmail (search msgtext takes some 10 min)

Reproduce (occurred >1 times. Though it's a timing issue, hard to reproduce - maybe with SIGSTOP KMail, or Netfilters):
During searching of local mails (50% CPU usage on a 2GHz dualcore system) POP3 UIDL obviously times out, opening requester stating the server allegedly "doesn't support UIDL"
o- Error requester "server does not support UIDL (see attachment)
This is bug #1: UIDL timeout mustn't be handled identically to error-response from server

o- i click "abort message download" at bottom right some times (because i know what will follow), then i click "ok" on error-requester **)
o- KONTACT coredumps (see attachment)
This is bug #2: kmail must NOT coredump

o- kmail deletes local list of mails already downloaded:
~/.kde/share/kmail/<user>@<serverdomain>:@pop.<serverdomain>:995 is void. 
seenUidList=<nullstring>
size before: ~121k, size after error: ~70byte
This is bug #3: list of downloaded mails MUST NOT be deleted on failure of UIDL.
This bug also appeared when kmail didn't segfault on error#2, it's directly related to UIDL-failure and 100% reproduceable (given you manage to get the UIDL not supported warning)


resulting problems: _all_msgs_ are downloaded a second time, to restore seenUidList. 


seen identically in SuSE10.1 version of Kontact

workaround: 
o- avoid lowmem/high-cpu-load when polling POP3.
o- when error happens: CANCEL DOWNLOAD IMMEDIATELY! Create filter to download all msgs older 1day to a temporary mail dir. Poll. (Disable filter. I keep it for catching errors during unattended polls)
o- *OR* CANCEL DOWNLOAD IMMEDIATELY! restore ~/.kde/share/kmail/<user>@<serverdomain>* from yesterday's backup.
o- then use <CTRL>+* to delete doublettes


jOERG