The WMF core features team tracks this bug on Mingle card https://mingle.corp.wikimedia.org/projects/flow/cards/363, but people from the community are welcome to contribute here and in Gerrit.

Unable to reproduce.

I looked at a few URLs displayed in the interface, and they're all escaped correctly.

Where did you get this link?

Example link taken from the workshop notes:
http://ee-flow.wmflabs.org/w/index.php?title=Talk:Flow_workshop&workflow=0506fc4aad826e5b09a3fa163e68c4ac&action=view#flow-post-0506fd0ed2010e132562fa163e68c4ac
So might be old and fixed now.

S, care to elaborate?

Andrew and S can't reproduce, so closed in Mingle, and here.

ErikB says square brackets are the way that MediaWiki can pass array arguments in URLs, that's a good reason to use them.

Reopening; S, you reproduced an example of this kind of URL in bug #56300 ;p

Also middle-clicking on "Older topics" (to open in a new tab) gives this: http://ee-flow.wmflabs.org/w/index.php?title=Special:Flow/Sandbox&topic_list[offset-id]=050805974f590e132562fa163e68c4ac&topic_list[offset-dir]=fwd&topic_list[limit]=5&workflow=0503c3d2e3d2ad56ca39fa163e68c4ac&action=view

And for reference, the 'fixed' version of quidditys example url is:

http://ee-flow.wmflabs.org/w/index.php?title=Special:Flow/Sandbox&topic_list%5Boffset-id%5D=050805974f590e132562fa163e68c4ac&topic_list%5Boffset-dir%5D=fwd&topic_list%5Blimit%5D=5&workflow=0503c3d2e3d2ad56ca39fa163e68c4ac&action=view

This is basically urlencode( 'topic_list[offset-dir]' ) which returns 'topic_list%5Boffset-dir%5D'

Another group of unescaped brackets, found in all "comment" links in history pages, eg.

http://ee-flow.wmflabs.org/w/index.php?title=User_talk:Quiddity&workflow=0506915cf3d0b62ef835fa163e68c4ac&action=topic-history

leads to

http://ee-flow.wmflabs.org/w/index.php?title=User_talk:Quiddity&topic[postId]=05093fcf969b34dffb6efa163e68c4ac&workflow=0506915cf3d0b62ef835fa163e68c4ac&action=view

Also in diffs, eg https://www.mediawiki.org/w/index.php?title=Talk:Sandbox&topic[newRevision]=050c87914c196f3747a890b11c28d448&topic[oldRevision]=050c878e4ad055356901842b2b77d2bd&workflow=050c553390ab9384b03a842b2b77e406&action=compare-revisions

(I'm not sure if these additional examples help, or if they'll all be automagically fixed via a single change somewhere? Let me know :)

Another fresh example. This is causing problems.
https://www.mediawiki.org/w/index.php?title=Talk:Sandbox&workflow=050defb4e07513ccf17190b11c2d680e#flow-post-050df155089fcfb51c0e782bcb016050

(Also, the mingle card needs to be re-opened, but I cannot change the "Accepted" status: https://wikimedia.mingle.thoughtworks.com/projects/flow/cards/363

(In reply to comment #9)

Another group of unescaped brackets, found in all "comment" links in history
pages, eg.

http://ee-flow.wmflabs.org/w/index.php?title=User_talk:
Quiddity&workflow=0506915cf3d0b62ef835fa163e68c4ac&action=topic-history

If I View > Source of that page, or select "added a comment" and View > Selection Source, I see %5B and %5D in the HTML, not square brackets.

(In reply to comment #10)

Also in diffs, eg

Again, if you View > Source the URLs of the "history page" and "20 days ago" links contain %5B and %5D, not brackets.

Note that when you mouse over these, and when you copy and paste them, your browser shows you '[' and ']' in place of the %5B and %5D -- try it with the URL in comment #8 -- so it's hard to tell what's going on. View > Source.

(In reply to comment #11)
That seems like a bug. The hyperlink ends at the square brackets. I don't know if Flow should be escaping URLs before submitting to Parsoid or if Parsoid is doing something wrong.

Another example: https://www.mediawiki.org/w/index.php?title=Talk:Flow&topic[postId]=050f90d90ce1662828ca90b11c28d444&workflow=050f6a5c16971e9b25a890b11c27a364

Please do not use [ and ] in the URL. This breaks wikimarkup (try making an external link with the URL above in it) and is just generally ugly and bad. The use of [ and ] in URLs is definitely a valid bug.

Possibly related: https://gerrit.wikimedia.org/r/110501

Change 110501 had a related patch set uploaded by EBernhardson:
Switch to underscores, because php mangles everything else

https://gerrit.wikimedia.org/r/110501

For the record, this was also reported at
https://www.mediawiki.org/w/index.php?title=Thread:Extension_talk:Scribunto/Framework_for_interactive_applications_on-wiki/reply_(2)&diff=898156

Change 110501 merged by jenkins-bot:
Switch to underscores, because php mangles everything else

https://gerrit.wikimedia.org/r/110501

This fix on ee-flow is causing problems in mini-pencil > Show changes links, see bug 60947

Links with topic[postId] in their URL are still present in Special:RecentChanges, specifically its "full-date" and "|post)" links. E.g.

http://ee-flow.wmflabs.org/w/index.php?title=User_talk:Maryana&workflow=rmk2kkoa3x4tnzsq&topic%5BpostId%5D=rmk2kkoa3x4tnzsq&action=post-history

The issue might lie in postLink() and postHistoryLink() in includes/Formatter/AbstractFormatter.php, which pass

'topic' => array( 'postId'

to UrlGenerator->buildUrl , maybe they should call generateBlockUrl() and a version that permits a particular action

Change 120732 had a related patch set uploaded by Bsitu:
Remove [] from URL

https://gerrit.wikimedia.org/r/120732

Change 120732 merged by jenkins-bot:
Remove [] from URL

https://gerrit.wikimedia.org/r/120732