[postgis-tickets] [PostGIS] #3380: "geometry crosses edge" with 1e-2 tolerance

[PostGIS]

#3380: "geometry crosses edge" with 1e-2 tolerance
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  Reporter:  strk      |      Owner:  strk
      Type:  defect    |     Status:  new
  Priority:  medium    |  Milestone:  PostGIS 2.1.9
 Component:  topology  |    Version:  2.1.x
Resolution:            |   Keywords:
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Comment (by strk):

 After loading the first two geometries node do exist that are closer than
 the given tolerance.
 Nodes 3 and 8 in the following image are 0.5e-2 units apart. Node 8
 existed as a vertex of the second geometry added (formed by edges 3,5,12)
 while node 3 was created during import as the intersection between the
 second geometry and the first one (formed by edges 2 and 4).

 There was no vertex where node 3 was created, so second geometry did not
 snap there.
 If we added all intersection points first and then re-snap linework
 against these new intersections, chances are this case would be fixed (in
 other words, use computed intersection points as snap references).

 [[Image(shp_error.png​)]]

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Ticket URL: <https://trac.osgeo.org/postgis/ticket/3380#comment:1>
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