Sorting Greek characters

[beerallica]

There's an abnormal behaviour in alphabetically sorted lists containing terms in Greek. The expected order would be Latin characters on top, then Greek; two consecutive lists. However, the Greek list is actually further split into two other lists, one with terms starting with an upper case character and the other with terms starting with lower case. So it's Latin Aa-Zz, then Greek Α-Ω, then Greek α-ω. A real-world example is a tag cloud. See this for example: ​http://www.tastefull.gr/tagcloud

[beerallica]

Update: The lists are five, not three:

1. Latin case-insensitive
2. Uppercase accented Greek
3. Uppercase non-accented Greek
4. Lowercase accented Greek
5. Lowercase non-accented Greek

The database collation is utf8mb4_unicode_ci and phpmyadmin sorts terms OK (e.g. Latin case-insensitive, then Greek case/accent-insensitive).

[desrosj]

Hi @beerallica,

My apologies that this ticket took so long to receive a response. I found this ticket while scrubbing a report for tickets missing a milestone.

Since it's been a substantial amount of time, I wanted to ask if you were still experiencing this in the latest version of WordPress (currently 6.6.1).

If so, could you provide a set of values as an example to see the behavior? Also, how are you sorting these values? Is this an alphabetic sort in a WP_Query? Something else? If you are a developer and comfortable in providing one, a unit test showing the bug would also be helpful.