Change 615555 had a related patch set uploaded (by MusikAnimal; owner: MusikAnimal):
[mediawiki/core@master] WatchAction: avoid unnecessary UPDATEs when expiry is unchanged

https://gerrit.wikimedia.org/r/615555

Change 615555 merged by jenkins-bot:
[mediawiki/core@master] WatchAction: avoid unnecessary UPDATEs when expiry is unchanged

https://gerrit.wikimedia.org/r/615555

Note again that this may be difficult to test manually. You could try observing the SQL log (with $wgDebugDumpSql set), or perhaps add logging/var_dump statements to WatchedItemStore::addWatchBatchForUser().

Change 620674 had a related patch set uploaded (by MusikAnimal; owner: MusikAnimal):
[mediawiki/core@REL1_35] WatchAction: avoid unnecessary UPDATEs when expiry is unchanged

https://gerrit.wikimedia.org/r/620674

Change 620674 merged by jenkins-bot:
[mediawiki/core@REL1_35] WatchAction: avoid unnecessary UPDATEs when expiry is unchanged

https://gerrit.wikimedia.org/r/620674

@MusikAnimal I find when the page is already permanently watched and I choose a permanent expiry value (e.g. "infinite") it is doing some INSERTs/DELETEs.

I am assuming because ExpiryDef::normalizeExpiry( $oldWatchedItem->getExpiry() ) returns null but ExpiryDef::normalizeExpiry( $expiry ); returns "infinity".

For example, editing a permanently watched page, keeping the edit expiry dropdown as "Permanent":

[DBQuery] WatchedItemStore::addWatchBatchForUser [0s] 127.0.0.1: INSERT IGNORE INTO `watchlist` (wl_user,wl_namespace,wl_title,wl_notificationtimestamp) VALUES (4,0,'Vnphyyblfr17',NULL),(4,1,'Vnphyyblfr17',NULL)
[DBQuery] WatchedItemStore::updateOrDeleteExpiries [0.001s] 127.0.0.1: DELETE `watchlist_expiry` FROM `watchlist_expiry`, `watchlist` WHERE we_item=wl_id  AND ((wl_user = 4 AND wl_namespace = 0 AND wl_title = 'Vnphyyblfr17') OR (wl_user = 4 AND wl_namespace = 1 AND wl_title = 'Vnphyyblfr17'))

Change 633830 had a related patch set uploaded (by MusikAnimal; owner: MusikAnimal):
[mediawiki/core@master] WatchAction: avoid UPDATE when old and new watch period is indefinite

https://gerrit.wikimedia.org/r/633830

Change 633830 merged by jenkins-bot:
[mediawiki/core@master] WatchAction: avoid UPDATE when old and new watch period is indefinite

https://gerrit.wikimedia.org/r/633830

@dom_walden Ready for QA again! I thought I'd ping you since this was incorrectly in your column for almost 2 months... now it's intentionally there :)

Change 633765 had a related patch set uploaded (by Samwilson; owner: MusikAnimal):
[mediawiki/core@REL1_35] WatchAction: avoid UPDATE when old and new watch period is indefinite

https://gerrit.wikimedia.org/r/633765

Change 633765 merged by jenkins-bot:
[mediawiki/core@REL1_35] WatchAction: avoid UPDATE when old and new watch period is indefinite

https://gerrit.wikimedia.org/r/633765

In T258649#6541199, @MusikAnimal wrote:

@dom_walden Ready for QA again! I thought I'd ping you since this was incorrectly in your column for almost 2 months... now it's intentionally there :)

Thanks!

The issue in T258649#6393420 has now been fixed.

The watchlist_expiry database table is only updated when the expiry changes.

I tested changing the expiry and watch status via Source Editor and Api:Edit.

As mentioned in T258649#6390877, I don't think you can see this in action on production.

Test Environment: Local vagrant MediaWiki 1.36.0-alpha (8e68310).