Hi,

I have noticed a number of bugs in the way Kmail2 (SC 4.8.2/4.8.3) handles local mail:

1.When copying or moving messages from one folder (remote or local) to another local folder, messages are initially placed into "new" subdirectory in the corresponding Maildir folder, regardless of the source message real status (e.g. even if messages are marked as read). Messages should go to "cur" subfolder instead.

2.Message files stored in "new" subfolder after copy/move operation lack any Maildir suffixes, e.g. ":2,S". I assume that the combination of bugs 1&2 is what causes infamous "unreadable messages" bug when clicking on a message header does not display it's text. This may happen due to race condition, see below.

3.Clicking on a newly copied message initiates the following process in the backgound: a) message file is moved from "new" to "cur" subfolder and b) message file is renamed by appending correct ":2,S" suffix to it. This process is ***extremely*** slow and is done in two steps (first move, then rename). In addition, there is absolutely no progress indication in the GUI or any notification whatsoever. This creates a major race condition and critical failure risk point. Because this operation is a) very slow, b) non-transactional (completed in at least two steps) and c) does not notify user of critical background operation in progress, a user would proceed working with folders as usual, e.g. clicking on message headers, attempt to further move/copy messages to another folders or delete them, etc. This would quickly exhaust backend capabilities (akonadi?) to manage file transactions and at some point provoke a crash due to race condition, leaving Maildir tree in unpredictable state and possibly corrupting akonadi database. After that, local mail folders structure becomes completely unaccessible through GUI.

4.A workaround for bugs 1&2 which prevents bug 3 from stricking is to do the follwoing immediately after copying/moving messages between folders in GUI: a) select all messages in the target folder (Ctrl-A), b) mark all messages as Unread (Ctrl-U), c) mark folder as read via its context menu, d) wait until all file operations in Maildir folders described in (3) are completed, tracking progess by watching actual status of the corresponding local Maildir folders (i.e. under ~/.local/share/loacl-mail). The latter may take a long time, up to 48 hours for a copy operation on a folder worth 90,000 messages (Core i7 3GHz, 6GB RAM, 10Krpm drive). If the operation is iterrupted before completion (e.g. by shutting down computer) your local folders will be rendered unusable and you will have to start from scratch.

5.An additional unrelated bug: neither Ctrl-A shortcut nor Edit->Select->All can select all messages in a folder with the message threading enabled and at least some message threads collapsed. You need to uncollapse all threads before issuing "select all" otherwise a number of messages will be randomly left out.


Reproducible: Always




Tested with Kubuntu Desktop 12.04 (x86_64) & KDE SC 4.8.2, reproduced after updating to SC 4.8.3.