[PostGIS] #6034: Missing node when adding overlapping line

[PostGIS]

#6034: Missing node when adding overlapping line
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  Reporter:  Lars Aksel Opsahl  |      Owner:  strk
      Type:  defect             |     Status:  new
  Priority:  medium             |  Milestone:
 Component:  topology           |    Version:  3.6.x
Resolution:                     |   Keywords:
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Comment (by strk):

 The rationale for the result being order-dependent is that by design we
 aim at keeping the existing topology as immutable as possible. The only
 reason why the existing topology changes is the limited space in which
 coordinates can be represented (floating point grid).

 What the mentioned PR does is using a controlled coordinate grid, but can
 only work if that grid is retained for all topology operations, so would
 require disabling the ability to pass a "tolerance" to topology population
 functions.

 An alternative implementation would be to support snapping incoming
 vertices to existing edges. That would still require slightly changing the
 existing topology, but at least we would reduce such change. The outcome
 would still be order dependent, in that you'd get the resulting node
 closer to the FIRST geometry that enters the topology.
-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/6034#comment:8>
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