Hi,
As part of auditing MediaWiki initialisation code[1], I noticed the state of our OutputHandler logic. It is currently implemented through a series of global functions in a dedicated includes file (separate from GlobalFunctions.php) which are then ad-hoc loaded (as needed) in WebStart.php.
I wouldn't consider these part of the public interface, because they were only conditionally included, and not in any autoloader. Stable usage would require a consumer to directly require the file from $IP/includes.
However, given that on many wikis they will appear to be consistently available, it is not impossible someone somewhere might use it somehow.
I found zero callers apart from the primary call in WebStart.php (plus some Api comments, and a false-positive match in a unit test).
Not usage in MediaWiki core or elsewhere in Wikimedia Git (per CodeSearch[2] and GitHub[3]).
As such, per our policy [4] I propose to refactor these without leaving back-compat aliases.
Feedback welcome at https://gerrit.wikimedia.org/r/420223
-- Krinkle
[1] https://phabricator.wikimedia.org/T189966 [2] https://codesearch.wmflabs.org/search/?q=wfOutputHandler [3] https://github.com/search?q=org:wikimedia+wfOutputHandler+-repo:wikimedia/me... [4] https://www.mediawiki.org/wiki/Deprecation#Removal_without_deprecation