When a a scene in a movie includes spanish speaking, what do they do in the spanish translation?

Ok in a english speaking movie, they see someone speaking spanish and it's a important part of the scene.


When you watch the spanish translation of the movie what do they do?


I've been wondering this for a long *** time.|||Well, sometimes they leave it like the original, and sometimes they change the Spanish parts for Portuguese or some other language. But sometimes they don't, and they ruin the movie like in the translated version of 'Spanglish' with Adam Sadler, in which the English speaking characters spoke some twisted and ridiculous version of Spanish and the Spanish speaking characters spoke like the original movie (plain Spanish).


Hope it helps! :)