[postgis-tickets] [PostGIS] #3464: ERROR: lwt_ChangeEdgeGeom could not construct face X, on the left of edge Y

[PostGIS]

#3464: ERROR: lwt_ChangeEdgeGeom could not construct face X, on the left of edge Y
-----------------------+----------------------------
  Reporter:  strk      |      Owner:  strk
      Type:  defect    |     Status:  new
  Priority:  medium    |  Milestone:  PostGIS Future
 Component:  topology  |    Version:  trunk
Resolution:            |   Keywords:  robustness
-----------------------+----------------------------

Comment (by strk):

 Reduced testcase:
 {{{
 SELECT DropTopology('bug3464');
 SELECT CreateTopology('bug3464');
 SELECT TopoGeo_AddLinestring('bug3464', g) FROM ( VALUES
 ('LINESTRING(634451.7803 4829559.1626,634485.78
 4829525.1627,634506.460690994 4829496.52791544)'
  ::geometry),
 ('LINESTRING(634451.7803 4829559.1626,634485.78
 4829525.1629,634506.460690994 4829496.52791544)')
 ) foo (g);

 SELECT TopoGeo_AddLinestring('bug3464',
 'LINESTRING(634446.780374345 4829591.16223176,634451.78032304
 4829559.16248522,634485.780040461 4829525.1627442,634488.530017153
 4829521.16277512)'
 ::geometry);
 }}}

 In this case we have a starting topology formed by 2 nodes and 2 edges
 almost parallel forming a single narrow face. The face has an area of
 0.0186 units and a perimeter of 166.81 units.
 Each edge has 3 vertices so the face has a total of 4 vertices (2 common
 edge endpoints and 2 differenti interior edge vertices).


 The line being added is also almost collinear. It has 4 vertices, one of
 which falling within the tiny face.

--
Ticket URL: <https://trac.osgeo.org/postgis/ticket/3464#comment:3>
PostGIS <http://trac.osgeo.org/postgis/>
The PostGIS Trac is used for bug, enhancement & task tracking, a user and developer wiki, and a view into the subversion code repository of PostGIS project.