List of steps to reproduce

• Go to w:vi:Special:ContentTranslation;
• Translate a random article from English to Vietnamese, make sure there are at least one category at the end of your translation;
• Publish it under a new title.

What happens?
Categorization wikilinks will look like [[Thể loại:Thể loại:Foo]] (for a real instance, see here).

What should have happened instead?
[[Category:Foo]] should have been translated to [[Thể loại:Foo]].