[postgis-tickets] [PostGIS] #3341: Serious rounding issues

[PostGIS]

#3341: Serious rounding issues
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  Reporter:  postgispaul  |      Owner:  pramsey
      Type:  defect       |     Status:  new
  Priority:  medium       |  Milestone:  PostGIS 2.1.9
 Component:  postgis      |    Version:  2.2.x
Resolution:               |   Keywords:
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Comment (by dbaston):

 I tried to reproduce this issue in JTS, which threw the familiar "This
 method does not support GeometryCollection arguments" exception.  It seems
 that the result of ST_Collect on polygons 600 and 1351 is not a valid
 MultiPolygon (the two polygons overlap).

 The comments in GEOS suggest that it should be blocking this operation, as
 JTS does, in geometry.h:
 https://github.com/libgeos/libgeos/blob/597a93df71c763205f5a021d35594b14db791a3f/include/geos/geom/Geometry.h#L626

 For this particular case, the rounding problem can be resolved by using
 ST_Union instead of ST_Collect.

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Ticket URL: <https://trac.osgeo.org/postgis/ticket/3341#comment:3>
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