Open a chat window and start to write a new message. Write it long, long, longer, so long that it is longer than the width of the window. Actually, sometimes empathy wraps the line, but it is kind of irregular, so when it doesn't break the line, it let's window grow. So if you write a long enough message, and even longer, window growths out of the desktop area.

Expected behavior:
a) however long message I have it should NEVER change the size of the window,
b) when the input box (after all line wrapping) growths over some predetermined height, I should get a scrollbar on the left.