On en beta, visit preferences and then hover over the link _Restore all default settings (in all sections)_
JS console reports an error
TypeError: page.revisions is undefined
it's coming from line 98 in ext.popups.core.js in curRequest.done
timestamp = new Date( page.revisions[ 0 ].timestamp ),
the API request I think it's handling is
http://en.wikipedia.beta.wmflabs.org/w/api.php?action=query&format=json&prop=extracts|pageimages|revisions|info&redirects=true&exintro=true&exsentences=2&explaintext=true&piprop=thumbnail&pithumbsize=300&rvprop=timestamp&inprop=watched&indexpageids=true&titles=Special%3APreferences%2Freset
which returns only
{"query":{\
"pageids":["-1"],
"pages":{"-1":{"ns":-1,"title":"Special:Preferences/reset","special":""}}}}
- There's no page.revisions for a Special page, so error. Test before accessing nested keys.
- It seems the code should give up before this anyway, since page.extract and page.thumbnail are both undefined. That would avoid showing empty popups with a timestamp.
- This gets through the popup link tests around line 516 because the link is to /wiki/Special:Preferences/reset, so no "#" or "?. There are other special page links that would pass this. Maybe the code should test if the namespace of the page is -1.
Version: master
Severity: normal
URL: http://en.wikipedia.beta.wmflabs.org/wiki/Special:Preferences?debug=1
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=64065