BUG #4872: Geometric function problem

The following bug has been logged online:

Bug reference: 4872
Logged by: Nick Roosevelt
Email address: nroose(at)thepinc(dot)com
PostgreSQL version: 8.2.5
Operating system: Linux
Description: Geometric function problem
Details:

I am getting bad results for distance between point and lseg. As you can
see below, the first result is correct, and the second is clearly not.

nroose_dev=> select version();
version
----------------------------------------------------------------------------
-------------------------------
PostgreSQL 8.2.5 on x86_64-unknown-linux-gnu, compiled by GCC gcc (GCC)
4.1.2 20070626 (Red Hat 4.1.2-13)
(1 row)

nroose_dev=> select point(0,0) <-> lseg(point(10,-100),point(10,450));
?column?
----------
10
(1 row)

nroose_dev=> select point(0,0) <-> lseg(point(10,-100),point(11,450));
?column?
------------------
100.498756211209
(1 row)

nroose_dev=>