A DESCRIPTION OF THE PROBLEM :
The contains method of class rectangle doesn't not consider a zero width or height rectangle to be contained in any other.
I found this situation in a custom paragraphview paint method. Some of the children were zero width (i think the \n) , and since i was using this method for indexing the text much head scratching ensued when sometimes the index got corrupted.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The contains (or any other method there) should specify that they don't accept zero dimension arguments. A work around is creating a method that checks that the max and min points are contained in the rectangle to check

URL OF FAULTY DOCUMENTATION :
http://download.java.net/jdk6/docs/api/java/awt/Rectangle.html#contains(java.awt.Rectangle)