Can't seem to replicate this on a local version.. not sure why this is happening.

(In reply to comment #0)

Luckily this won't effect the average visitor who will not have gadgets
installed.

Some gadgets are enabled by default.

https://gerrit.wikimedia.org/r/#/c/49071/
https://gerrit.wikimedia.org/r/#/c/51301/

Max lies (according to Maryana)
On Maryana's account I'm seeing the following gadgets load:

/w/index.php?title=MediaWiki:Gadget-popups.js&action=raw&ctype=text/javascript&532528798

/w/index.php?title=MediaWiki:Gadget-ReferenceTooltips.js&action=raw&ctype=text/javascript&508635914

https://en.m.wikipedia.org/w/index.php?title=MediaWiki:Gadget-edittop.js&action=raw&ctype=text/javascript&507509831

/w/index.php?title=MediaWiki:Gadget-metadata.js&action=raw&ctype=text/javascript&421724048

Several mobile exceptions thrown breaking her mobile experience.

Uncaught ReferenceError: hookEvent is not defined index.php:7671
Uncaught ReferenceError: importStylesheet is not defined index.php:19
Uncaught ReferenceError: getElementsByClassName is not defined

mgrover wrote:

Change on 02/28 were abandoned

https://gerrit.wikimedia.org/r/61028 (Gerrit Change Ibc43852486041b940464310201654e4fa6c53c6e) | change APPROVED and MERGED [by jenkins-bot]

Did the core change get applied? gadgets still seem to be leaking..

The Gadgets change https://gerrit.wikimedia.org/r/#/c/60954/ is not yet live:

maxsem@fenari:/h/w/c/php-1.22wmf3/extensions/Gadgets$ grep wfRunHooks Gadgets_body.php
maxsem@fenari:/h/w/c/php-1.22wmf3/extensions/Gadgets$

Interesting - the changeset is present (via git log) in the Gadgets extension submodule of the php-1.22wmf3 branch; I guess it just hasn't been updated/deployed in production.