[PostGIS] #6140: ST_AddNodeModFace creates invalid topology

[PostGIS]

#6140: ST_AddNodeModFace creates invalid topology
------------------------+---------------------------
 Reporter:  strk        |      Owner:  strk
     Type:  defect      |     Status:  new
 Priority:  medium      |  Milestone:  PostGIS 3.6.5
Component:  topology    |    Version:  3.6.x
 Keywords:  robustness  |
------------------------+---------------------------
 Spinoff of #6129: ST_AddNodeModFace creates invalid topology:
 {{{
 SELECT DropTopology('ttt');
 SELECT NULL FROM CreateTopology('ttt');

 SELECT NULL FROM ST_AddIsoNode('ttt', 0,
 '01010000005163B45884333540352259FDE66A5140'); -- start node of edge 1
 SELECT NULL FROM ST_AddIsoNode('ttt', 0,
 '0101000000685E205B88333540B7363CF4E66A5140'); -- start node of edge 2
 SELECT NULL FROM ST_AddIsoNode('ttt', 0,
 '0101000000831D215B88333540107B41F4E66A5140'); -- end node of both edges

 SELECT NULL FROM ST_AddEdgeModFace('ttt', 1, 3,
 '0102000000030000005163B45884333540352259FDE66A51406043FEC3BA333540C0BFF081E66A5140831D215B88333540107B41F4E66A5140');
 SELECT NULL FROM ST_AddEdgeModFace('ttt', 2, 3,
 '010200000002000000685E205B88333540B7363CF4E66A5140831D215B88333540107B41F4E66A5140');
 -- this edge crosses the previous
 SELECT 'invalidities', * FROM ValidateTopology('ttt'); -- Requires
 https://trac.osgeo.org/postgis/ticket/6138 fix to see this
 }}}

 Note in order to spot the invalidity we need the fix for #6138
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Ticket URL: <https://trac.osgeo.org/postgis/ticket/6140>
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