Version:           1.13.5 (using Devel) 
OS:                Linux

While trying to debug bug 211885, I stumbled upon a weird behaviour of KMail, as described in comment #65 over there:

----8<----
[...] I see another weird thing, KMail is renaming/removing the
search folders randomly.  I actually saw it first in comment #63:  I created a
Search Folder named test and exited.  After I restarted Kmail, I had two Search
Folders: test and Test.  Well, I didn't have enough coffee yet, so I discarded
it as a personal brainfuck.  I removed both the folders.

Now I tested it again and kept the Last Search folder name, restarted KMail,
and I suddenly had my old folder called test again.  With the old search
settings.  WTF?

So I removed test again, did another search called Last Search, shut down KMail
and had a look at the ~/.kde/share/apps/kmail/search directory:

mss@Otherland:~/.kde/share/apps/kmail/search$ cat Last\ Search 
[Search Folder]
Base=.1081015519.directory/INBOX
Recursive=true
contentsA=testest
fieldA=<message>
funcA=contains
name=<unknown>
operator=and
rules=1

So far so good.  Now I restarted KMail and had no Search Folder at all!  The
file Last Search was removed from the harddisk as well.

Something is very odd around here.  But KMail doesn't crash.
----8<----

It seems like KMail got confused internally about its searches.  Next is the debug output etc. of KMail starting with an existing search folder Last Search ("Can not find parent folder for  Last Search"), once it runs I created a new search called test.  Note that KMail swallows the last character of the old search folder name (".Last Searc.index.sorted").

mss@Otherland:~$ kmail
Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
kmail(8667) KMFolderMgr::removeFolderAux: Can not find parent folder for  Last Search 
kmail(8667) KMFolder::updateIndicatorIcon: Could not read image from "" 
kmail(8667) KMFolder::updateIndicatorIcon: Could not read image from "" 
kmail(8667) KMFolder::updateIndicatorIcon: Could not read image from "" 
kmail(8667) KMFolder::updateIndicatorIcon: Could not read image from "" 
kmail(8667) KMKernel::recoverDeadLetters: Unable to open autosave file "1270548288.2252.700YL" 
QMetaObject::invokeMethod: No such method KUniqueApplication::loadCommandLineOptionsForNewInstance()
kmail(8667)/kdecore (KConfigSkeleton) KCoreConfigSkeleton::writeConfig:
kmail(8667)/kdecore (KConfigSkeleton) KCoreConfigSkeleton::writeConfig:
kmail(8667) KMFolder::updateIndicatorIcon: Could not read image from "" 
kmail(8667) KMFolder::updateIndicatorIcon: Could not read image from "" 
kmail(8667) KMFolder::updateIndicatorIcon: Could not read image from "" 
kmail(8667) KMFolder::updateIndicatorIcon: Could not read image from "" 
registerWindow Invalid WindowMenu.Registrar! 
mss@Otherland:~$ QInotifyFileSystemWatcherEngine::addPaths: inotify_add_watch failed: No such file or directory
QFileSystemWatcher: failed to add paths: /home/mss/.config/ibus/bus
Bus::open: Can not get ibus-daemon's address. 
IBusInputContext::createInputContext: no connection to ibus-daemon 
kmail(8667)/kio (KIOJob) KIO::TransferJob::slotData: mimeType() not emitted when sending first data!; job URL = KUrl("imap://xxxx:143/INBOX/;UID=7984;SECTION=BODY.PEEK[]") data size = 3054 

mss@Otherland:~$ kmail(8667) FolderStorage::rename: Failed to rename the sorted file from "/home/mss/.kde/share/apps/kmail/search/.Last Search.index.sorted" to "/home/mss/.kde/share/apps/kmail/search/.Last Searc.index.sorted" 
kmail(8667) FolderStorage::rename: Failed to rename the sorted file from "/home/mss/.kde/share/apps/kmail/search/.Last Searc.index.sorted" to "/home/mss/.kde/share/apps/kmail/search/.test.index.sorted" 
kmail(8667)/kdecore (KConfigSkeleton) KCoreConfigSkeleton::writeConfig:
kmail(8667)/kdecore (KConfigSkeleton) KCoreConfigSkeleton::writeConfig:

Reproducible: Always




OS: Linux (x86_64) release 2.6.32-23-generic
Compiler: cc