looks like this is specific to one of my folders. My threading is standard mailing list basically boils down to: #0 0x00007fb92a7bee41 in MessageList::Core::MessageItem::topmostMessage (this=0x39732b0) at /data/kde/src/5/kde/pim/messagelib/messagelist/src/core/messageitem.cpp:525 525 if (!parent()) { [Current thread is 1 (Thread 0x7fba57dce900 (LWP 19580))] #0 0x00007fb92a7bee41 in MessageList::Core::MessageItem::topmostMessage() (this=0x39732b0) at /data/kde/src/5/kde/pim/messagelib/messagelist/src/core/messageitem.cpp:525 #1 0x00007fb92a7bee88 in MessageList::Core::MessageItem::topmostMessage() (this=0x3c9b830) at /data/kde/src/5/kde/pim/messagelib/messagelist/src/core/messageitem.cpp:529 repeat forever and ever
if I change the aggregation to "Activity by Date, Flat", then I can access the folder contents again without hitting the infinite recursion. but as soon as I select the Aggregation back to "Standard Mailing List" it gets stuck again.
In the web-interface for my email: * made a temporary folder * moved all the messages from the bad folder to the temporary folder things work fine in the temporary folder from KMail now.
Created attachment 109477 [details] full backtrace (gzip'd due to size)
*** Bug 389804 has been marked as a duplicate of this bug. ***
possible fix at https://phabricator.kde.org/D10255
this was fixed by Albert a couple months ago.