[3.0] Save one recipient's copy of a personal message, not everybody's

[albertlast]

Description

A row in pm_recipients is one member's copy of one personal message, and (id_pm, id_member) is its primary key.

Received::save() named only the PM in its WHERE clause, and set id_member in the SET clause:

UPDATE {db_prefix}pm_recipients
SET
    id_member = {int:member},
    ...
WHERE id_pm = {int:id}

So the statement asks the database to hand every recipient's copy to the same member. On any PM with more than one recipient that is a duplicate key error, every time, for anything that saves — labelling it, marking it read, deleting it.

Reproduced on a clean install: send a PM to two members, then apply a label to it from the inbox.

Database Error: Duplicate entry '4-2' for key 'smf_pm_recipients.PRIMARY'
File: /var/www/html/Sources/PersonalMessage/Received.php
Line: 239

The member belongs in the WHERE clause rather than the SET clause — a copy's owner is its identity, not something a save changes. With that, both recipients keep their own row and their own state; the unread flag on the copy that was not being saved survives, where before the whole statement was rejected.

Labels are owned by a member too, so the same applies to the labelled messages the save clears out. It deleted every label on that PM:

DELETE FROM {db_prefix}pm_labeled_messages
WHERE id_pm = {int:current_pm}
    AND id_label NOT IN ({array_int:labels})

pm_labels rows carry an id_member, so a PM labelled by two recipients has a row per member here, and saving one member's labels threw away the other's. Fixture with (label 2, pm 4) owned by member 1 and (label 4, pm 4) owned by member 2, saving member 1's labels:

	rows left
before	2-4
after	2-4, 4-4

That line is only reachable for a PM that has other recipients once the update above works, which is why the two are one change. The subquery is over a different table, so it is fine on MySQL and on PostgreSQL.

Found while sweeping the personal messages area. Two other faults sit alongside this one and are going up separately: Received::loadByPm() collapses every recipient of a PM into one, and the per-message label drop-down submits a value applyActions() no longer accepts.

Issues References (Fixes|Related|Closes)

n/a