Add validation rule based on Spoofchecker::isSuspicious()

[nicolas-grekas]

See https://php.net/spoofchecker.issuspicious

We could then add the annotation automatically in maker-bundle when the intl extension is available.

[MatTheCat]

I did a little digging and PHP’s Spoofchecker is in a sorry state:

• its name is wrong (should be SpoofChecker).
• isSuspicious’s second argument &$errorCode seems to always be null (I guess it should match ICU’s checkResult).
• setRestrictionLevel is not documented (but works).
• setAllowedLocales requires comma-separated locales in a single string.
• no way to set allowed characters sets (ICU provides a setAllowedChars method).
• setChecks documentation is wrong (some checks concern confusability, not spoof detection).
• SINGLE_SCRIPT check should be replaced by SINGLE_SCRIPT_RESTRICTIVE level since ICU 51.
• ANY_CASE check modifier does not serve any purpose since ICU 58.
• MIXED_NUMBERS check constant is missing (you can use its value 128 though).
• HIDDEN_OVERLAY check constant is missing (you can use its value 256 though).
• constants are not documented.

[nicolas-grekas]

Thanks for digging. This could be worth a bug report on php-src, WDYT?

[MatTheCat]

Yes, I think both php-src and php-doc-en need a little dusting on that matter!

[nicolas-grekas]

(please don't forget to open an issue on php-src)