[QGIS-trac] [Quantum GIS] #3156: wms getmap request with unknown epsg

[Quantum GIS]

#3156: wms getmap request with unknown epsg
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   Reporter:  francesco                                  |              Owner:  nobody       
       Type:  bug                                        |             Status:  new          
   Priority:  critical: causes crash or data corruption  |          Milestone:  Version 1.6.0
  Component:  Build/Install                              |            Version:  1.5.0        
   Keywords:  wms getMap EPSG                            |   Platform_version:               
   Platform:  All                                        |           Must_fix:  No           
Status_info:  0                                          |  
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 Hello all,
 we noticed that qgis in not able to build the WMS getMap Request if an
 EPSG is not recognized by qgis (meaning that it is not in the tbl_srs
 table of the srs.db database).
 since the 1.5 version we can easily add the unknown epsg just adding a
 record in that table, but you can understand that in not nice to have to
 maintain that table manually. For example, in that DB it is not present
 the EPSG:102113, that is the Web Mercator (Google) for Esri. Just adding
 the record in the tbl_srs table then qgis is able to build the correct
 getMap request, including the SRS parameter with the EPSG chosen by the
 user. Otherwise it include the CRS:84.
 What we can not understand is why for qgis it is not enough to read the
 SRS from the capabilities file and let the user to choose the EPSG even
 when the EPSG is not in the  tbl_srs table.
 We have this problem mainly with our customized SRS that is an UTM ED50
 with a false northing of -4000000, so we have a WMS with the EPSG:NONE or
 EPSG:0, but for correct add the WMS layer in qgis we had to add a record
 in the tbl_srs (with this prj: "+proj=tmerc +lat_0=0 +lon_0=9 +k=0.9996
 +x_0=500000 +y_0=-4000000 +ellps=intl +units=m +no_defs") and it works. In
 this case we have to send the customized srs.db to the user that wish to
 visualize our WMS in qgis: really not nice.
 For example, the WMS url to check this behaviour is:
 http://servizigis.regione.emilia-
 romagna.it/arcgis/public_sgss/geocatalogo_mappa/MapServer/WMSServer?
 We already noticed this behaviour in the past (2009 March) in the 1589
 ticket, but then had no time to follow the development.

 Thanks,
 francesco

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Ticket URL: <https://trac.osgeo.org/qgis/ticket/3156>
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