Steps to reproduce the issue

Add a new categoy with a Unicode name in a multiple languages website.
Add a new article and fill the title/alias with any of these examples using no-break space like   or invisible whitespace character U+00a0:

 test
test 
test test

Then set the category for this new article to be a "Unicode language" category name and save it.
Make sure Unicode Aliases is set to Yes in configuration.

Expected result

Open the article url/webpage as usual.

Actual result

The url will have %20 in that article alias which will cause the page url not to open and throw ERR_TOO_MANY_REDIRECTS error.