„ character ("„", U+201E, double low-9 quotation mark) not cleared from url (slug)

[tometzky]

A character "„" („, U+201E, double low-9 quotation mark) is not not cleared from slug and permalink url in %postname%.

It is very popular character in post titles in many European countries because it is used in smart quotes in MS Word and other text processors for example in Polish.

To reproduce:

1. Go to ​http://demo.opensourcecms.com/wordpress/wp-admin/ and login as admin with passsword "demo123".
2. Switch to "Month and name" in permalink settings.
3. Create a post with a title of "foo „bar” foo"
4. The post gets a permalink of ​http://demo.opensourcecms.com/wordpress/2012/06/foo-%e2%80%9ebar-foo/ which does not work.

Additional info:
Non-English usage of quotation marks
​http://en.wikipedia.org/wiki/Non-English_usage_of_quotation_marks

[SergeyBiryukov]

#19820