Change 885856 had a related patch set uploaded (by Bartosz Dziewoński; author: Bartosz Dziewoński):

[mediawiki/extensions/DiscussionTools@master] Fix interaction of "Add topic"/"Read as wiki page" buttons with categories

https://gerrit.wikimedia.org/r/885856

Change 885856 merged by jenkins-bot:

[mediawiki/extensions/DiscussionTools@master] Fix interaction of "Add topic"/"Read as wiki page" buttons with categories

https://gerrit.wikimedia.org/r/885856

The selectors may be optimized:

Replace $( '#page-secondary-actions > *' ) with $( '#page-secondary-actions' ).children():

• Chrome (which is an optimized browser), for 100,000 iterations: from 216 ms to 78 ms
• Pale Moon (which lacks such optimizations), for 10,000 iterations: from 1790 ms to 16 ms (!)

Replace $( '.catlinks[data-mw="interface"]' ) with $( '.catlinks' ).filter( '[data-mw="interface"]' ):

• Chrome, for 10,000 iterations: from 596 ms to 35 ms
• Pale Moon, for 10,000 iterations: from 1162 ms to 84 ms

Change 886996 had a related patch set uploaded (by Bartosz Dziewoński; author: Bartosz Dziewoński):

[mediawiki/extensions/DiscussionTools@master] Optimize selectors in mobile hacks

https://gerrit.wikimedia.org/r/886996

Thanks @Od1n, done. Feel free to just submit patches if you have the time.

(For anyone who'd like to verify that it's faster, you can copy some handy benchmarking code from T324523#8445297.)

Change 886996 merged by jenkins-bot:

[mediawiki/extensions/DiscussionTools@master] Optimize selectors in mobile hacks

https://gerrit.wikimedia.org/r/886996

Thanks for the patch :)

I had a look at this issue, and it might (to be confirmed) be helpful to move the optional .return-link from #bodyContent to the following #page-secondary-actions.

See in skin.mustache: Currently, the html-minerva-subject-link message is appended to #bodyContent, but it might rather be prepended to the following #page-secondary-actions.

That would be semantically cleaner, and might help to simplify the workaround you had to add here.

Even better, we might insert between #bodyContent and #page-secondary-actions the following:

{{#html-minerva-subject-link}}
    <div class="post-content">{{{.}}}</div>
{{/html-minerva-subject-link}}

(not tested, and of course the CSS of .return-link would probably have to be tweaked)

Then, the workaround of this ticket could be simplified to something like $( '#content' ).children( '.post-content' ).children().length (selector maybe to be refined, and caution, the .post-content class is quite generic and used elsewhere).