User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:90.0) Gecko/20100101 Firefox/90.0

Steps to reproduce:

Thunderbird 91.0b5 (64-bit) on Linux 5.8.0-63-generic #71~20.04.1-Ubuntu SMP x86_64
Calendar syncs with owncloud 10.7.0.4 using TB's CalDAV, no Calendar Extension installed

1. Add tasks in owncloud
2. Sync the calendar
3. Open the "Today pane"
4. Switch Today pane to "Tasks" or "Events and Tasks" view
5. Right-click in the Tasks view in the Today pane to open the context menu
6. Choose "Filter Tasks"
7. Chose any option from the submenu

Actual results:

The filter doesn't change, the same Tasks are visible and if you repeat steps 1-6 above, the submenu still shows "Current Tasks".

Expected results:

The filter should change to the selected one.

Tried 91.0b5 (64-Bit) on Windows 10 Pro 21H1 64Bit with the same wrong result.

I see the same with the Home calendar on my computer using Thunderbird 91.0b5 on Fedora 34 Workstation.

Pushed by geoff@darktrojan.net:
https://hg.mozilla.org/comm-central/rev/c1f5b0bf7260
Stop using a command to filter tasks in the Today Pane. r=mkmelin

Missing uplift request here?

There's nothing to uplift to right now. 92 beta begins this week.

Comment on attachment 9234184 [details]
Bug 1723293 - Stop using a command to filter tasks in the Today Pane. r=mkmelin

[Approval Request Comment]
Regression caused by (bug #): not sure, something m-c broke a long time ago, I suspect
User impact if declined: tasks can't be filtered in the Today Pane
Testing completed (on c-c, etc.): in 92.0b1
Risk to taking this patch (and alternatives if risky): low

Comment on attachment 9234184 [details]
Bug 1723293 - Stop using a command to filter tasks in the Today Pane. r=mkmelin

[Triage Comment]
Approved for esr91

Thunderbird 91.0.3:
https://hg.mozilla.org/releases/comm-esr91/rev/fe8f67bf4960

Verified testing the 91.0.3 release, release candidate on Windows 10.