BUG #4967: polygon @> point incorrect for points close to shared borders

The following bug has been logged online:

Bug reference: 4967
Logged by: Paul Matthews
Email address: plm(at)netspace(dot)net(dot)au
PostgreSQL version: 8.3.7
Operating system: Linux Open Suse 11.0 + 11.1
Description: polygon @> point incorrect for points close to shared
borders
Details:

Have two polygons, both with many vertex, sharing a common edge. Several
thousand points where then tested to see which of the polygons the points
fell into using the "polygon @> point" operator.

A number of points close to the common border claimed they fell into both of
the polygons.

A quick perl+DBI+GD application was developed to plot both the polygons, the
polygon boundaries, as well as the points that thought they where in both.

This showed points close, but still several pixels away from the shared
border, thinking they where in both.

Guidance on this matter would be appreciated.