+++ This bug was initially created as a clone of Bug #1817867 +++

112.0a1 (2023-02-20) (64-bit)

Mouse action directly on the threads expand/collapse toggle seems to have the same problem. Beware of artifacts when multiple messages are selected (which is the only thing which seems to work).

STR1

• Threaded view with threads
• select only msg 1 of open thread
• press cursor left on msg 1 to collapse thread

STR2

• Threaded view with threads
• select msg 2 of open thread, then shift+cursor up to select msg 1, too (now both selected, focus on msg 1)
• press cursor left on msg 1 to collapse thread
• press cursor right to expand thread

Actual

• STR1: For collapsed thread, still shows single message
• STR2: For Expanded thread, still shows multi-message view although only msg 1 is selected.

Expected:

• STR1: For collapsed thread, need to show multi-message in msg reader
• STR2: For expanded thread with only first msg selected, need to show single message in msg reader

Pushed by geoff@darktrojan.net:
https://hg.mozilla.org/comm-central/rev/c4eafa02981b
Update the displayed message when collapsing or expanding threads. r=mkmelin

Comment on attachment 9319122 [details]
Bug 1817871 - Update the displayed message when collapsing or expanding threads. r=#thunderbird-reviewers

[Triage Comment]
Approved for beta

Thunderbird 111.0b1:
https://hg.mozilla.org/releases/comm-beta/rev/1da216b7ba5b