[postgis-tickets] [PostGIS] #4711: ST_Union loses precision on complex multilinestring geometries

[PostGIS]

#4711: ST_Union loses precision on complex multilinestring geometries
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  Reporter:  dannytoone  |      Owner:  pramsey
      Type:  defect      |     Status:  new
  Priority:  medium      |  Milestone:  PostGIS 3.1.0
 Component:  postgis     |    Version:  3.0.x
Resolution:              |   Keywords:
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Comment (by mdavis):

 A further note on the cause of the overlay errors.  It's not the overlap
 of the `lic_group`s that causes the problem, it's the geometry in each
 group itself.  The group polygons are made non-overlapping by splitting
 them along the lines that split overlapping circles (which is a clever
 technique, by the way).  However, the splitting and differencing involved
 introduces some numeric "jitter".  The result is polygons which contain
 nearly-coincident lines along their boundaries.  This is a classic cause
 of overlay robustness issues.  And it's something that snapping takes care
 of very effectively.

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Ticket URL: <https://trac.osgeo.org/postgis/ticket/4711#comment:6>
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