[postgis-tickets] [PostGIS] #2407: [regression] ST_CurveToLine and ST_LineToCurve are not symmetric (was: st_linetocurve behaviour change)

[PostGIS]

#2407: [regression] ST_CurveToLine and ST_LineToCurve are not symmetric
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 Reporter:  mjurce   |       Owner:  pramsey      
     Type:  defect   |      Status:  new          
 Priority:  medium   |   Milestone:  PostGIS 2.0.4
Component:  postgis  |     Version:  2.0.x        
 Keywords:           |  
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Comment(by strk):

 I changed the summary again because I think the real problem here is being
 unable to go from curve to line and back to curve in a consistent way.
 This is a regression because there are known case in which 1.5.x succeeded
 in doing it.

 Here's an example small test input:
 {{{
 CIRCULARSTRING(718006.92 114480.27, 718006.381 114478.609, 718004.78
 114477.91)
 }}}

 Passing the above to ST_CurveToLine and then to ST_LineToCurve produces a
 COMPOUNDCURVE in 1.5 and a LINESTRING (the _same_ linestring generated by
 ST_CurveToLine) in 2.0.

 The 1.5 final output (curve):
 {{{
  COMPOUNDCURVE(CIRCULARSTRING(718006.92 114480.27,718006.396201402
 114478.625952602,718004.826280993 114477.909987011),(718004.826280993
 114477.909987011,718004.78 114477.91))
 }}}

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/2407#comment:18>
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