Seems only one remaining issue. See subticket. Can move on once resolved.

WIP patch can be demoed in story time.

At least it seems that the issue is related to the fact that there's code[1] or there are templates[2] to add a preset of groupnames to the mapframes show attribute. Currently this is used as convenient shortcut so authors do not have to add the commonly used groups by hand on every mapframe. This shortcut works ( or worked ) because until recently empty groups were hidden in the layer controls even if they're explicitly added to in the show attribute.

Changing the status as resolved. I just closed the ticket where this ticket got merged into. I'm not sure if they are related but at least it's clear from the one example above that the issue here got fixed.

The error was altered and downgraded to a warning, If I'm not mistaken its not appearing anymore. I guess it makes sense to create a new ticket when there's a new lead.

I think there were a couple of issues involved here including the mentioned failed auto positioning but also the broken parity on the map servers T316365: Restore the map data health and parity between clusters. Fixes for the underlying issues should be deployed.

The main issues seem to be solved here. Whenever this becomes an urgent matter again there should be a new task I guess. Thanks to everyone involved.

The first issue with the zoom levels seems fixed. At least I can not see it anymore when visiting the linked page. ( it uses zoom=9 where the map is supposed to be broken/empty, but actually it isn't empty ).

I guess this was done with https://gerrit.wikimedia.org/r/c/mediawiki/services/kartotherian/+/866579 and the related updates.

In T331992#8704522, @Reedy wrote:

I didn’t say it was the same issue ;)

I was mostly curious if it was also only replicable on some PHP versions :)

In T331992#8703595, @Reedy wrote:

Is this on your dev wiki/similar?

What PHP version? Can you test it on other PHP versions? As T330464: Import failed: XML error at line 1: Validation failed: no DTD found ! caused issues on PHP 8.2 (but not seemingly on other versions)...

In T144777#4439056, @Mholloway wrote:

This will need rechecking.

Test worldCopyJump with different scenarios, especially edge cases around the 180° meridian e.g. [1] or from T195654 T313615 T229174
Make sure zooming in and clicking markers at the edges does not let the features "jump away"

The idea works in principle but could really give weird effect on objects near/spanning the anti-meridian:

Test possible alternative that prevents zooming out https://leafletjs.com/reference.html#map-fitworld

This option does not help very much here. It could be used to block users from zooming out too far, but users could still move "off" the world and can see strangeness around the edges of the anti-meridian.

I took the freedom to change the ticket a bit. While implementing T304076: Nearby feature for maps we used a different clustering library that eventually will replace prunecluster and the Wikivoyage nearby feature. There were already some questions from the community on giving clustering to features added via mapframe and maplink so I wanted to give these requests a new more up to date home where feedback can be collected.

I guess this ticket is well enough solved with the implementation of T307695: Display coordinate markers in Kartographer maps from QID which uses P625 as source. Storing a complete copy of OSM node data is really out of scope and not an useful approach. But I guess the major intend of having a way to show single markers from an external source was fulfilled so I'll mark this as resolved rather then declined.

Done in T320692: Disable Wikivoyage nearby and enable Show Nearby on de.wikivoyage see also https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Kartographer/+/843467 that introduced a kill switch on the extension to disable that feature when required.