Does the presence of dry saliva with a foul odor on the side of the mouth, and the sensation of its taste in the mouth, affect the fast?

Merely tasting saliva in the mouth does not affect the validity of the fast, and the presence of its taste does not necessitate swallowing it. If a fasting person swallows saliva while asleep or unintentionally, this does not harm the fast; because swallowing saliva does not invalidate the fast unless one intentionally swallows it after it has exited the mouth.