[PostGIS] #6122: Incoming linework vertices do not form nodes when below tolerance from existing edges

[PostGIS]

#6122: Incoming linework vertices do not form nodes when below tolerance from
existing edges
------------------------+---------------------------
 Reporter:  strk        |      Owner:  strk
     Type:  defect      |     Status:  new
 Priority:  medium      |  Milestone:  PostGIS 3.8.0
Component:  topology    |    Version:  master
 Keywords:  robustness  |
------------------------+---------------------------
 As mentioned in https://trac.osgeo.org/postgis/ticket/6034#comment:16 the
 current topology code doesn't make any effort at finding cases in which
 incoming vertices would end up being below tolerance from existing edge
 segments. Such support exists for *nodes* but nodes are computed in the
 floating precision model of GEOS (rather than on a fixed precision model)
 so there will be no node unless there is a proper intersection with an
 existing edge.

 This problem causes many robustness issues like #6034, #5862, #5786 and
 more

 Possible solutions include:

   1. Snapping existing edges to incoming vertices (WIP:
 https://gitea.osgeo.org/postgis/postgis/pulls/280)
   2. Compute noding on a fixed precision model (WIP:
 https://gitea.osgeo.org/postgis/postgis/pulls/243)
-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/6122>
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.