I can confirm this issue, and I believe it to be a bug with how forum threads are looked up. Perhaps one of the team here can confirm the issue?
Steps to reproduce:
1. Create a thread using greek characters
2. Right click, and “copy link” then paste in new tab. This WORKS.
3. Now copy the URL directly out of the address bar and paste in new tab. This DOESN’T WORK
The difference I’m seeing is that the outputted forum URLs are encoded using lowercase a-f characters, but if you copy from the address bar (depending on browser or OS) the encoding letters are A-F uppercase.
For example:
ce%bf – accepted by bbPress and given the correct page
CE%BF – goes to 404
Normal WordPress pages can handle either just fine.
I’ve tested this for a bit and got the same results in both Chrome and Firefox on OS X. It really looks like a bug where bbPress can’t tell the difference, or it’s not an exact match. Either way, this could be a big issue! To users, the links look exactly the same, and they can have issues sharing links.
Thanks! Hoping to get some more feedback here.
Best regards
