support queries across anti-meridian line

- the envelope query would have values above 180, which is not valid CQL

Author: ebuckley

ckanext/spatial/plugin.py

@@ -317,6 +317,9 @@ def _params_for_solr_spatial_field_search(self, bbox, search_params):
             +spatial_geom:"Intersects(ENVELOPE({minx}, {miny}, {maxx}, {maxy}))
 
         '''
+        if bbox['maxx'] > 180:
+            bbox['maxx'] = -180 + (bbox['maxx'] - 180)
+
         search_params['fq_list'] = search_params.get('fq_list', [])
         search_params['fq_list'].append('+spatial_geom:"Intersects(ENVELOPE({minx}, {maxx}, {maxy}, {miny}))"'
                                         .format(minx=bbox['minx'], miny=bbox['miny'], maxx=bbox['maxx'], maxy=bbox['maxy']))