[PostGIS] #6143: [topology] False edge crossing detected

PostGIS trac at osgeo.org
Fri Oct 9 00:33:40 PDT 2026


#6143: [topology] False edge crossing detected
----------------------+---------------------------
 Reporter:  strk      |      Owner:  strk
     Type:  defect    |     Status:  new
 Priority:  blocker   |  Milestone:  PostGIS 3.7.0
Component:  topology  |    Version:  master
 Keywords:            |
----------------------+---------------------------
 The new lwline_have_nonboundary_2d_intersection function committed in
 d03570c8597d49e4ca382283b3385c22f52a5b7a returns true with this input:

 L1: LINESTRING(-1000000000000 -1000000000000, -1 0.0001)
 L2: LINESTRING(100000 -10000, -1 -0.00000000001)

 It can be checked like this:
 > select
 topology.TopoEdgesHaveInteriorIntersection('LINESTRING(-1000000000000
 -1000000000000, -1 0.0001)'::geometry, 'LINESTRING(100000 -10000, -1
 -0.00000000001)'::geometry);

 But GEOS Finds them non crossing:
 > select ST_IsSimple(ST_Collect('LINESTRING(-1000000000000 -1000000000000,
 -1 0.0001)'::geometry, 'LINESTRING(100000 -10000, -1
 -0.00000000001)'::geometry));

 and ST_Distance reports them being 0.00010000001 units apart.
-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/6143>
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