[postgis-devel] [PostGIS] #211: Inverse transformation borks when fed +nadgrids=@null

[PostGIS]

#211: Inverse transformation borks when fed +nadgrids=@null
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 Reporter:  pramsey  |       Owner:  mcayland     
     Type:  defect   |      Status:  new          
 Priority:  medium   |   Milestone:  postgis 1.3.7
Component:  postgis  |     Version:  1.3.X        
 Keywords:           |  
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 Create the Google mercator system:
 {{{
 insert into spatial_ref_sys (srid, proj4text) values (900913, '+proj=merc
 +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +units=m
 +k=1.0 +nadgrids=@nell +no_defs');
 }}}
 Then project into and out of it (it's the google->lonlat step that
 actually fails).
 {{{
 postgis13=# select
 st_astext(st_transform(st_transform('SRID=4326;POINT(-71.057810000000003
 42.358919999999998)',900913),4326));
 WARNING:  transform: -38 (failed to load NAD27-83 correction file)
                      st_astext
 ---------------------------------------------------
  POINT(-1.11408409697064e-05 6.64126844571044e-06)
 (1 row)
 }}}
 This is not a proj problem:
 {{{
 Heron-2:~ pramsey$ invproj +proj=merc +a=6378137 +b=6378137 +lat_ts=0.0
 +lon_0=0.0 +x_0=0.0 +y_0=0 +units=m +k=1.0 +nadgrids=@null +no_defs
 -7910119.22608518 5214896.47356734
 71d3'28.116"W   42d21'32.112"N
 }}}
 Nor does it manifest in 1.4.

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/211>
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