[PostGIS] #6089: wrong node used when adding a new long line

[PostGIS]

#6089: wrong node used when adding a new long line
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  Reporter:  Lars Aksel Opsahl  |      Owner:  strk
      Type:  defect             |     Status:  new
  Priority:  medium             |  Milestone:
 Component:  topology           |    Version:  master
Resolution:                     |   Keywords:  snap
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Comment (by strk):

 I've attached a further simplified test, with a single segment snap target
 of length `1.5054470047841826e-07` and a single segment snap source
 (subject):
 https://trac.osgeo.org/postgis/attachment/ticket/6089/t6089-snap.sql

 The reason why the incoming line (snap subject/source) ends up snapping to
 BOTH vertices of the existing edges (snap target) is because both those
 vertices are below tolerance:

 {{{
 =# select n, st_distance(( select g from t6089.source), st_pointn(( select
 g from t6089.target), n)) from generate_series(1,2) n;
  n |      st_distance
 ---+-----------------------
  1 |                     0
  2 | 9.999999406318238e-08
 (2 rows)
 }}}

 So there is no snapping to "wrong node" (as you put it).

 [[Image(snapping-multiple.png)]]
-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/6089#comment:6>
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