search box T,B must be zero

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@48852 15284696-431f-4ddb-bdfa-cd5b030d7da7

vector/v.in.ogr/geom.c

@@ -121,6 +121,8 @@ centroid(OGRGeometryH hGeom, CENTR * Centr, struct spatial_index *Sindex,
 	    double x, y;
 
 	    Vect_line_box(Points, &box);
+	    /* centroid's z is set to zero */
+	    box.T = box.B = 0;
 	    Vect_spatial_index_select(Sindex, &box, List);
 
 	    for (i = 0; i < List->n_values; i++) {