Fixed in https://gerrit.wikimedia.org/r/#/c/21411/

https://gerrit.wikimedia.org/r/#/c/21411/ will not fix this completely, Still there are two font preferences - one from ULS and one from existing mediawiki preferences. Both will conflict each other for edit boxes. So we need a better way to handle these two options. But I think priority can be reduced with this fix.

The bug is back again. Only this time, the style attribute says only "font-family: sans-serif;"

Fixed in gerrit I5c35c848

Some regression caused this again.

Fix submitted in
https://github.com/wikimedia/jquery.webfonts/pull/2

See also bug 39992. This is currently occurring on Wikidata.org.

By default users now have "font-family: sans-serif;" inline on the <textarea> instead of the browser default (which in most browsers is a monospace font for <textarea>).

The MediaWiki preference related to this is not relevant, as it doesn't do anything by default.

…and here we go again. The textarea on MediaWiki.org has “font-family: sans-serif;” style inline when using Czech [cs], see e.g. http://www.mediawiki.org/w/index.php?title=Project:Sandbox&action=edit&uselang=cs

My guess is I9dd87f44 (or https://github.com/santhoshtr/jquery.webfonts/commit/1f67cf2bf9ac435a6772eb66f080b118c0e10661).

I switched my preferences to make the textarea always use monospaced font, which seems to stop ULS from messing with the textarea for now.

Mormegil, if you don't mind I suggest to keep this old report closed and continue on bug 53734 which is its reincarnation.