[geos-devel] question about GEOSUnion?

[LiN YongHeng]

Hello everyone,
I have a question about GEOSUnion().
I give value to g1 and g2 like below:
GEOSGeom g1 = "POLYGON ((1  3, 1  3, 1  6, 1  6, 1 3))"  and GEOSGeom g2 =
"POLYGON ((1  3, 1  3, 1  6, 1  6, 1 3))"  , but if I make union operation
like GEOSGeom g3 =
GEOSUnion(g1, g2), it give me result like "GEOMETRYCOLLECTION EMPTY".
Does anyone can tell me why?
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