[QGIS-trac] Re: [Quantum GIS] #1487: QGIS fails to recognise Shapefile projection

[Quantum GIS]

#1487: QGIS fails to recognise Shapefile projection
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        Reporter:  marisn                            |         Owner:  nobody       
            Type:  bug                               |        Status:  closed       
        Priority:  major: does not work as expected  |     Milestone:  Version 1.0.2
       Component:  Projection Support                |       Version:  1.0.0        
      Resolution:  fixed                             |      Keywords:               
Platform_version:                                    |      Platform:  Gentoo       
        Must_fix:  No                                |   Status_info:  0            
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Changes (by wonder):

  * status:  new => closed
  * resolution:  => fixed

Comment:

 This has been fixed in r10398.

 Frank - to explain the inner working of the CRS recognition: given a proj4
 string, qgis tries to match it to database. Reason for this is to find out
 EPSG id, srid and name of the projection. If it fails doing exact match,
 it goes through the database entries and compares the two projections
 using OSRIsSame (resp. OSRIsSameGeogCS). If this search fails too, it
 creates CRS just using the proj4 string (projection name and ids are not
 resolved). If everything fails, it just uses wgs84 or some other default
 CRS.

 This might not be the best logic (personally I'm not really confident with
 roboustness of OSRIsSame), so any ideas for improvement are mostly
 welcome.

 Martin

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Ticket URL: <https://trac.osgeo.org/qgis/ticket/1487#comment:4>
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