[PostGIS] #5782: XX000: Corrupted topology: adjacent edges 33 and -32 bind different face (1 and 0)

[PostGIS]

#5782: XX000: Corrupted topology: adjacent edges 33 and -32 bind different face (1
and 0)
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  Reporter:  Lars Aksel Opsahl  |      Owner:  pramsey
      Type:  defect             |     Status:  new
  Priority:  high               |  Milestone:  PostGIS 3.5.0
 Component:  postgis            |    Version:
Resolution:                     |   Keywords:
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Comment (by strk):

 The starting topology has two edges that are almost coincident (3 and 4,
 in the picture):

 [[Image(topology.png)]]

 It looks like those two edges influence the code as if I change them to be
 further apart, as in the next picture, the subsequent addition of a line
 does not result in a broken topology:

 [[Image(magnified_topology.png)]]

 The last incoming line (in yellow in the picture) only touches edge 5 and
 is otherwise open, not closing any ring. For some reason the code thinks
 one of the side faces of it is face 1 which is the tiny face between edges
 3 and 4. It must be the code that determines which face contains a new
 point (endpoinnt of incoming line) by lookinng at the closest edge: in
 this case the "closest edge" is probably 3 or 4 and we get the side wrong.
 I'll verify by testing addition of a single point.
-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/5782#comment:7>
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