Two complaints in #71, one cause. Deleting from the keyboard left
`focusId` pointing at a row that was no longer in the list, and nothing
moved it.
The confirmation appearing "every other message": `targetIds()` falls
back to the focused id, so the second `#` re-targeted the message the
first one had just deleted. The optimistic update had already moved that
message into Deleted Items, so it read as a permanent delete -- and a
permanent delete always confirms, whatever "Confirm before deleting" is
set to. The dialog was correct about the message it was asked about; it
was asked about the wrong one.
`k` jumping to the top: `moveFocus` reads `ids.indexOf(focusId)`, which
was -1 for the departed row, and -1 is treated as "before the first
row". Adding -1 to that clamps to 0.
Both explain why the mouse was fine: clicking sets focus to a row that
exists.
Focus now moves to whatever slid into the deleted row's place, honouring
"After archiving or deleting" -- the row below by default, the one above
when set to newer -- and clears when the folder empties. `moveFocus`
also no longer reads a missing row as index 0; it falls back to where
the list thinks it is.
Verified in the browser against the mock, since arithmetic tests cannot
prove the wiring: with confirmation off, two deletes in a row both go
through silently, focus stepping e4 to e5 to e6 as rows close up; then
`k` moves up exactly one instead of to the top of the list.
jcoffey-dev
2e33b4c467