This is a bit tricky to describe and to reproduce. Actually it seems this does only happen exactly once per mail. To be hold: I use the "Fance with Clickable Status" theme. Reproducible: Sometimes Steps to Reproduce: 1. Open all groups and close all threads. 2. Use quick search to filter for a specific word (e.g. about) 3. Now all groups _and_ threads are opened 4. Close all threads (e.g. Ctrl+,) 5. Click on an arbitrary mail Actual Results: All threads in the group of the selected mail (even if this mail doesn't have athread itself) are opened again which makes it very difficult to search in the mail for a specific one if the message list changes on every click, especially when browsing mailng lists with lots of traffic. Expected Results: The threads stay collapsed or in the previous state.
This bug has only been reported for versions before 4.14, which have been unsupported for at least two years now. Can anyone tell if this bug still present? If noone confirms this bug for a Framework-based version of kmail2 (version 5.0 or later, as part of KDE Applications 15.12 or later), it gets closed in about three months.
Just as announced in my last comment, I close this bug. If you encounter it again in a recent version (at least 5.0 aka 15.08), please open a new one unless it already exists. Thank you for all your input.