[3.0] Say whether the label being put on a PM is going on or coming off

[albertlast]

Description

The drop down beside each message in the inbox offers two lists of labels — the ones that can be applied, and the ones that can be taken off — and gave both of them a bare label ID as their value:

// Are there any labels which can be added to this?
<option value="', $label['id'], '">', $label['name'], '</option>
...
// ... and are there any that can be removed?
<option value="', $label['id'], '">&nbsp;', $label['name'], '</option>

Nothing downstream can tell those two apart, and PersonalMessage::applyActions() does not try. It reads an add_ or rem_ prefix and skips anything else:

elseif (str_starts_with($action, 'add_')) {
    $type = 'add';
    ...
} elseif (str_starts_with($action, 'rem_')) {
    $type = 'rem';
    ...
}

if (isset($type) && \in_array($type, ['add', 'rem']) && ...) {

So picking a label from that drop down did nothing at all. smf_pm_labeled_messages stays empty, no error is logged, and the page reloads looking exactly as it did.

The values are written this way because SMF 2.1 read a bare value as "toggle this label" — it had an else { $type = 'unk'; } branch, and further down, if (array_key_exists(...) && $type !== 'add') unset(...); elseif ($type !== 'rem') .... 3.0 dropped that branch and kept the markup, which is why the drop down looks fine and does nothing.

The template knows perfectly well which of the two lists it is drawing, so it says so. That is also exactly what loadLabelChoices() in this same file builds for the whole-folder drop down ("add_" + i, "rem_" + i), which has been the only working way to label a PM.

Verified the round trip on the inbox:

step	drop down offers	pm_labeled_messages
start	add_2 Alpha, add_3 Beta	empty
pick add_2	add_3 Beta, rem_-1 Inbox, rem_2 Alpha	2-1
pick rem_2	add_2 Alpha, add_3 Beta	empty

Nothing new in the error log either way.

Issues References (Fixes|Related|Closes)

n/a