[postgis-devel] [PostGIS] #1571: ST_ChangeEdgeGeom lets you break topology

[PostGIS]

#1571: ST_ChangeEdgeGeom lets you break topology
----------------------+-----------------------------------------------------
 Reporter:  strk      |       Owner:  strk         
     Type:  defect    |      Status:  new          
 Priority:  medium    |   Milestone:  PostGIS 2.1.0
Component:  topology  |     Version:  trunk        
 Keywords:            |  
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Comment(by strk):

 Thanks Paul for helping with the concept:
 http://postgis.refractions.net/pipermail/postgis-
 devel/2012-February/018640.html

 I think we're now clear for the semantic.
 Next step would be algorithmical: how to find out if the constraint gets
 broken by a movement ?

 Here's some random examples for proving your mind over the concept:

 Source:
 {{{
 o--------o
       o
 }}}

 Some Targets:
 {{{
 o        o
 |     o  |       NOT VALID
 '--------'



 o  ,-----o
 |  |  o          VALID
 '--'

 o  ,-----o
 |  |  o .-.      VALID
 |  `----' |
 '---------'

    ,---------.
    `-------. |
 o  ,-----o | |
 |  |  o    | |   VALID
 |  `-------' |
 '------------'
 }}}

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/1571#comment:5>
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