Polygon of modelgrid : Handle the case lon/lat = 0

ModelGrid.py

@@ -96,10 +96,13 @@ def corners(indF, proj, istart, jstart, lon, lat) :
         polyll=proj.ijll(polyg)
         centll=proj.ijll([[istart+ij[0],jstart+ij[1]]])[0]
         #
-        allon.append([p[0] for p in polyll])
-        allat.append([p[1] for p in polyll])
+        lons = [p[0] if p[0]!=0 else 0.0000001 for p in polyll]
+        lats = [p[1] if p[1]!=0 else 0.0000001 for p in polyll]
+ 
+        allon.append(lons)
+        allat.append(lats)
         #
-        sphpoly=polygon.SphericalPolygon.from_lonlat([p[0] for p in polyll], [p[1] for p in polyll], center=centll)
+        sphpoly=polygon.SphericalPolygon.from_lonlat(lons, lats, center=centll)
         #
         areas.append((sphpoly.area())*EarthRadius**2)
         cornerspoly.append(sphpoly)