At least under OS 6.0--and several devices have released versions of this OS--the text-entry field does not extend beyond one line when entry wraps to the next. You can tell you are typing, but you only see the characters from the first line entered.
This is a significant handicap!
The previously mentioned approach of turning off "enter to send" functionality does not help. A new-line is inserted by enter, but only the first line is visible in the field.
Please advise and add to the bug list!