There's an extremely irritating and error-prone selection styling error when right-clicking on a set of multiple selected messages. Should fix this asap as it's very exposed, too.

Regression seen on Daily 114.0a1 (2023-04-20) (64-bit), Win10.

• Kindly asking Alice for a regression range if possible.
• Elizabeth might have insights as she worked on related bug 1819277.
• Richard may be able to help with styling analysis.

STR

1. Select some messages in 3-pane message list
2. Right-click on selection

Actual (see screenshot)

• Visually semi-deselects all but the clicked message: Only the right-clicked message of the selected set looks fully selected, all others have a "dimmed" semi-selection
• Unclear selection status: now I'm not sure which messages I'll be acting on - just the bright one or the whole set? Happy guessing!
• Error-prone: Easy to overlook semi-selection and be mislead to think only one message is selected. Dataloss if I shift-delete based on the false/misleading visual state: Only one looks fully selected, but more will get deleted.

Expected

• Maintain the regular selected styling for all selected messages even after right-clicking on one message out of the selected set, as we're still acting on all of them.

I'd say this is because of the new behavior that the message under the right click becomes the active state. This should be expanded to all before selected messages.
This looks more like a JS issue than a CSS issue.

(In reply to Thomas D. (:thomas8) from comment #0)

Created attachment 9329558 [details]
Screenshot: Semi-selected messages after right-click on selected set of messages
Regression seen on Daily 114.0a1 (2023-04-20) (64-bit), Win10.

• Kindly asking Alice for a regression range if possible.

^^ see comment 0

#1 Regression window: Selection are dimmed when right clicking.
https://hg.mozilla.org/comm-central/pushloghtml?fromchange=94c23b92346d9f276c65dfcb15bf553754a52feb&tochange=68b4f9618db5609ea64da1b37bc08175a77fc1a6
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=64b0a4a734ea6dc90afe519e7b9cde48d27dc20e&tochange=c0aa2400128384a72f6c58c2cea4ddd15a6900eb

Suspect: Bug 1820744

#2 Regression window: Selection are dimmed when right clicking, but highlighted for right-clicked item only.
https://hg.mozilla.org/comm-central/pushloghtml?fromchange=8da75a3a1eb4afa733c7c3695d71e008fe892aa3&tochange=6f6b36b285682b22c95073709bbd44e5925edc7c
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=0565e88d945287090080a36edc83f77f52b605f4&tochange=b8472c1213cb9bf7fd96d1139a9fd15cf10b3bd1

Regressed by: Bug 1821804

I'd say this is because of the new behavior that the message under the right click becomes the active state.

I guess this bug would be resolved by reverting the this. Which should happen, see bug 1817731

(In reply to Magnus Melin [:mkmelin] from comment #4)

I'd say this is because of the new behavior that the message under the right click becomes the active state.
I guess this bug would be resolved by reverting the this. Which should happen, see bug 1817731

I don't think so. Making the right-clicked message focused/selected or not is independent of the correct selection behaviour here. Right-click on selection must never alter the selection. The focus/selection on right-click is only relevant for previously unselected messages (i.e. right-clicking outside the selection without holding Ctrl). Right-click with Ctrl outside selection must not change or add to selection.

Right-click on selection must never alter the selection.

But currently it does that.

(In reply to Magnus Melin [:mkmelin] from comment #6)

Right-click on selection must never alter the selection.

But currently it does that.

It doesn't. It only alters the visual appearance of the selection (this bug), but most context menu actions will still apply to the full selection of multiple messages.

As a simple fix, we can adjust the background color of selected items.

• Address how items are displayed in and out of focus

Pushed by alessandro@thunderbird.net:
https://hg.mozilla.org/comm-central/rev/ec072b8546f2
Adjust background of multiple selected messages. r=Paenglab

Comment on attachment 9330775 [details]
Bug 1829194 - Adjust background of multiple selected messages. r=paenglab

[Triage Comment]
Approved for beta

Thunderbird 114.0b6:
https://hg.mozilla.org/releases/comm-beta/rev/8545f842ef1a