The following call
preg_match( '/[^\p{S}\p{Nd}]/us', '4' )
correctly returns 0 on Zend but returns 1 under HHVM on MediaWiki appservers such as mw1017. It does not seem to occur on osmium.
The same occurs with various other permutations:
preg_match( '/[^\p{P}\p{Nd}]/us', '4' )
preg_match( '/[^\p{Z}\p{Nd}]/us', '4' )
preg_match( '/[^\p{Xps}\p{Nd}]/us', '4' )
preg_match( '/[^\p{Xsp}\p{Nd}]/us', '4' )
preg_match( '/[^\p{M}\p{Ll}]/us', 'a' )
preg_match( '/[^\p{N}\p{Ll}]/us', 'a' )
preg_match( '/[^\p{P}\p{Ll}]/us', 'a' )
preg_match( '/[^\p{S}\p{Ll}]/us', 'a' )
preg_match( '/[^\p{Z}\p{Ll}]/us', 'a' )
preg_match( '/[^\p{Xps}\p{Ll}]/us', 'a' )
preg_match( '/[^\p{Xsp}\p{Ll}]/us', 'a' )
preg_match( '/[^\p{M}\p{Lu}]/us', 'A' )
preg_match( '/[^\p{N}\p{Lu}]/us', 'A' )
preg_match( '/[^\p{P}\p{Lu}]/us', 'A' )
preg_match( '/[^\p{S}\p{Lu}]/us', 'A' )
preg_match( '/[^\p{Z}\p{Lu}]/us', 'A' )
preg_match( '/[^\p{Xps}\p{Lu}]/us', 'A' )
preg_match( '/[^\p{Xsp}\p{Lu}]/us', 'A' )
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**Version**: wmf-deployment
**Severity**: normal