Certainly, that page on mediawiki.org wouldn't be updated until the patch is actually merged :)

Makes sense... =D

Not sure how to update the documentation - directly in API:Siteinfo?

Isn't that just because the scripts for mysql / mariadb and sql-lite use

INSERT (OR) IGNORE

while postgres does NOT use the equivalent

ON CONFLICT DO NOTHING`

? (see https://github.com/search?q=repo%3Awikimedia%2Fmediawiki%20filearchive-fa_major_mime-patch-fa_major_mime-chemical.sql&type=code)

In T324910#8485601, @Tgr wrote:

In T324910#8484979, @Krinkle wrote:

It seems though that the relevant API already exists today. I don't know what upcoming feature or use case prompted this task, but that means it isn't blocked on a new API as it already exists.

As long as RawAction isn't deprecated (whatever that would mean for an action), it makes sense to aim for feature parity IMO.

@Simontaurus would the action API work for your use case? [...] The content is wrapped in JSON (there is no way to get just the raw content string); other than that I don't think there's any disadvantage IMO. [...]

The usecase at this point is to place a machine readable document behind an URI. Specifically, it's about json-schema, which are referenced both absolutely and mutually among themselves.
(see also json-schema.org and T324933 )
In this way, for example, a category can specify the schema for structured data that must be followed by pages in that category.

In T324910#8458712, @Tgr wrote:

Would you like to submit a core patch?

On stackoverflow there are some suggestions for a more robust solution for this limitation of XPath1,
e. g. using regex or iterate over all nodes an check for default namespace declarations.
https://stackoverflow.com/questions/1245902/remove-namespace-from-xml-using-php

Thanks for providing the patch. Problem fixed: Named subobjects now create link texts from display title as expected ("DisplayTitle" in the given example)