Having gone through and re-read sections of the CIRCULARSTRING code, it is amazing how much easier the code is to read without the confusion of a curve being either a CIRCULARSTRING or LINESTRING as per the SQL-MM spec. The resulting commit compiles & installs cleanly for me, passes "make check" and also Regina's torture script. Please let me know if I accidentally broke anything :)
git-svn-id: http://svn.osgeo.org/postgis/trunk@3520 b70326c6-7e19-0410-871a-916f4a2858ee