Several of the Rectangle methods do not protect properly against integer
overflow.

In earlier releases a few of the hit testing methods were upgraded to
perform their calculations in a way that avoids integer overflow. See
bugs 4280606, 4394562, 4394565, and 4394579 for more information on the
earlier overflow work.

This unfortunately leaves several of the other methods that modify the
rectangle still suffering from potential overflow conditions. Bug 4491273
was submitted to request a documentation update to reflect the overflow
possibilities, but it was decided by the engineering team to instead fix
as many of the overflow possibilities as could be fixed within the constraints
of the fact that the data is stored in exposed integer fields. The remaining
limits imposed by the 32-bit integer storage would then be documented. The
methods that are being modified are:

setRect(double, double, double, double)
translate(int, int)
union(Rectangle)
add(int, int)
add(Rectangle)
grow(int, int)

These methods need to store their results into a Rectangle object and so are
constrained in the final answer by the 32-bit integer range, but they can at
least protect against overflow during their intermediate calculations.