[geos-devel] CVS GEOS union results

[Howard Butler]

According to the JTS Test builder the results of this union should be 
as follows:

A
--------------------------
POLYGON ((601289.2369585614651442 4621930.3517169132828712, 
601296.6117308996617794 4621943.1251973006874323, 
601331.2527470423374325 4621943.1251973006874323, 
601348.5732551137916744 4621913.1251973006874323, 
601331.2527470423374325 4621883.1251973006874323, 
601296.6117308996617794 4621883.1251973006874323, 
601284.4943894973257557 4621904.1130482675507665, 
601277.1196171591291204 4621891.3395678801462054, 
601242.4786010164534673 4621891.3395678801462054, 
601225.1580929449992254 4621921.3395678801462054, 
601242.4786010164534673 4621951.3395678801462054, 
601244.3377801323076710 4621951.3395678801462054, 
601235.3788347869412974 4621966.8569164043292403, 
601252.6993428583955392 4621996.8569164043292403, 
601287.3403590010711923 4621996.8569164043292403, 
601304.6608670725254342 4621966.8569164043292403, 
601287.3403590010711923 4621936.8569164043292403, 
601285.4811798851005733 4621936.8569164043292403, 
601289.2369585614651442 4621930.3517169132828712))

B
--------------------------
POLYGON ((601289.3684807127574459 4621895.6708746394142509, 
601279.5020359900081530 4621895.4660383407026529, 
601284.4943894973257557 4621904.1130482675507665, 
601289.3684807127574459 4621895.6708746394142509))

Result
--------------------------
POLYGON ((601289.2369585615 4621930.351716913, 601296.6117308997 
4621943.125197301, 601331.2527470423 4621943.125197301, 
601348.5732551138 4621913.1251973, 601331.2527470423 
4621883.125197301, 601296.6117308997 4621883.125197301, 
601289.3684807126 4621895.67087464, 601279.5020359906 
4621895.466038343, 601277.1196171591 4621891.33956788, 
601242.4786010165 4621891.33956788, 601225.158092945 
4621921.33956788, 601242.4786010165 4621951.339567881, 
601244.3377801323 4621951.339567881, 601235.3788347867 
4621966.856916403, 601252.6993428584 4621996.856916403, 
601287.3403590011 4621996.856916403, 601304.6608670725 
4621966.856916403, 601287.3403590011 4621936.856916404, 
601285.4811798851 4621936.856916404, 601289.2369585615 4621930.351716913))

GEOS CVS HEAD is currently giving this as a result (using C++ API and 
the default precision for the geometry factory... double, right?)

MULTIPOLYGON (((601289.2369585614651442 4621930.3517169132828712, 
601296.6117308996617794 4621943.1251973006874323, 
601331.2527470423374325 4621943.1251973006874323, 
601348.5732551137916744 4621913.1251973006874323, 
601331.2527470423374325 4621883.1251973006874323, 
601296.6117308996617794 4621883.1251973006874323, 
601284.4943894973257557 4621904.1130482675507665, 
601277.1196171591291204 4621891.3395678801462054, 
601242.4786010164534673 4621891.3395678801462054, 
601225.1580929449992254 4621921.3395678801462054, 
601242.4786010164534673 4621951.3395678801462054, 
601244.3377801323076710 4621951.3395678801462054, 
601235.3788347869412974 4621966.8569164043292403, 
601252.6993428583955392 4621996.8569164043292403, 
601287.3403590010711923 4621996.8569164043292403, 
601304.6608670725254342 4621966.8569164043292403, 
601287.3403590010711923 4621936.8569164043292403, 
601285.4811798851005733 4621936.8569164043292403, 
601289.2369585614651442 4621930.3517169132828712)), 
((601289.3684807127574459 4621895.6708746394142509, 
601279.5020359900081530 4621895.4660383407026529, 
601284.4943894973257557 4621904.1130482675507665, 
601289.3684807127574459 4621895.6708746394142509)))

Any ideas what might be going on?

Howard