[QGIS-trac] Re: [Quantum GIS] #2497: ftools: difference tool (asymmetrical difference) does not work with moltipolygon geometries

[Quantum GIS]

#2497: ftools: difference tool (asymmetrical difference) does not work with
moltipolygon geometries
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        Reporter:  lutra                             |         Owner:  cfarmer      
            Type:  bug                               |        Status:  new          
        Priority:  major: does not work as expected  |     Milestone:  Version 1.5.0
       Component:  Python plugins and bindings       |       Version:  HEAD         
      Resolution:                                    |      Keywords:               
Platform_version:                                    |      Platform:  All          
        Must_fix:  Yes                               |   Status_info:  0            
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Comment (by lutra):

 Replying to [comment:1 cfarmer]:
 > Difference between multipolygon (and multiline) features works ok for me
 here, could you please attach a test dataset to replicate this error?
 >
 > -Carson


 Hi Carson,

 here I am again.


 So you can test the following shapes:

 http://mapserver.uevora.pt/~mapserver/viaria_evora_buffer_shp.zip

 http://mapserver.uevora.pt/~mapserver/interdita2_shp.zip


 Use the first as input layer and the second as difference layer.


 The first one was obtained by buffering a line vector. The second one was
 obtained by unioning 3 shapes obtained by buffering (2) a line vector and
 a point vector plus a polygon vector. This line, point and polygon were
 obtained initially by clipping bigger vectors.

 Only ftools was used for this exercise.

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Ticket URL: <https://trac.osgeo.org/qgis/ticket/2497#comment:3>
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