Bug: Matching Locale with Negotiate Locale does not work in some cases as expected

[crustamet]

PHP Version

8.3

CodeIgniter4 Version

4.5.5

CodeIgniter4 Installation Method

Manual (zip or tar.gz)

Which operating systems have you tested for this bug?

Linux

Which server did you use?

apache

Database

No response

What happened?

public string $defaultLocale = 'en-US';
public bool $negotiateLocale = true;
public array $supportedLocales = ['en-US','en-GB'];

why like this ? Because i want to show different content for United Kingdom vs United States

Steps to Reproduce

to reproduce you must place UK first instead of the US

The app does not have {locale} specific routes

in your view just put it should always be equal to the $Request->getLocale()

In my Language Folder
I have them in separate folders en-US and en-GB

In the request header i have this
accept-language: en-US,en-GB;q=0.9,en;q=0.8,ro;q=0.7

and if i switch to English - United Kingdom the accept-language changes to this
accept-language:en-GB;en-US;q=0.9,en;q=0.8,ro;q=0.7

Expected Output

When i have the United Kingdom version as my default i should see

when i get the Locale from the Request the en-GB version instead of the en-US

echo $Request->getLocale(); always output en-US in both cases
it should return the en-GB version !

The problem is why is this happening is because of this file
https://github.com/codeigniter4/CodeIgniter4/blob/develop/system/HTTP/Negotiate.php#L181

There is a loop over the Supported languages and the first two are both english from my SupportedLocales so it returns only the first Locale matched and not the exact matched one.

I have test this it only works when i change the order from the
App Config
public array $supportedLocales = ['en-US','en-GB']; always shows the US page even if you have the default language en-GB
public array $supportedLocales = ['en-GB','en-US']; always shows the GB page even if you have the default language en-US.

Anything else?

No response

[michalsn]

The problem here is that we want a loose comparison for locales most of the time.

Setting the last variable to false should help: https://github.com/codeigniter4/CodeIgniter4/blob/develop/system/HTTP/Negotiate.php#L130

Should we make that configurable? Is it worth creating another config file/property? Personally, I'm not convinced, although I would like to hear other people's opinions.

The instant solution would be to extend the Negotiate class and declare changed service in app/Config/Services.php file - which I recommend.

Anyway, not really a bug, maybe a missing feature.