Search function and non-english characters case sensitivity issue

[alexpi]

Description

When performing a site search using non-english characters, the search is performed with case sensitivity, so for example in Greek, searching for the word 'Βάρος', does not match 'βάρος' (Same word with a lowercase first letter).

Expected behavior

Your setup

Kirby Version

3.9.6.1

Your system (please complete the following information)

• Device: Desktop PC
• OS: Windows 10
• Browser: Chrome, All
• Version: 117

Additional context

I wrote about this issue in the forum, and @rasteiner explained the issue to me. I am quoting his answer (I hope that's ok):

"Kirby relies on the PCRE2 regex engine of PHP to find matches, it passes the i flag to the regex to make the search case insensitive, but in PCRE2 world, i only works for the ranges [a-zA-Z] (that’s only the 52 symbols of the English alphabet, like: it also [doesn’t match ü with Ü]. I guess Kirby could change that regular expression to [also include the u (Unicode) flag], that would fix the upper / lower case issue."

Is it possible that a small change to Kirby's code could fix this termporarily?

[rasteiner]

If you want to test it, change this line to

$preg    = '!(' . implode('|', $words) . ')!iu';

(just add a u after the i)

It should make a difference:
https://onlinephp.io?s=s7EvyCjg5eLlSk3OyFdQD88sycgvLVEotVJQ11MoKEpNj89NLEnO0FCvOTfp3Jrzjef2n2-qyVTXUVBQP7cJJqCuqaCnoBSTp2QNM0dBQQFkFCFzSoEGYTUHAA%2C%2C&v=8.2.7%2C8.1.20%2C8.0.29

[alexpi]

Yes it works!