Fixed #25662 -- Allowed creation of empty GEOS geometries.

django/contrib/gis/geos/collections.py

@@ -25,9 +25,6 @@ class GeometryCollection(GEOSGeometry):
         "Initializes a Geometry Collection from a sequence of Geometry objects."
 
         # Checking the arguments
-        if not args:
-            raise TypeError('Must provide at least one Geometry to initialize %s.' % self.__class__.__name__)
-
         if len(args) == 1:
             # If only one geometry provided or a list of geometries is provided
             #  in the first argument.

django/contrib/gis/geos/linestring.py

@@ -35,7 +35,14 @@ class LineString(ProjectInterpolateMixin, GEOSGeometry):
         if not (isinstance(coords, (tuple, list)) or numpy and isinstance(coords, numpy.ndarray)):
             raise TypeError('Invalid initialization input for LineStrings.')
 
+        # If SRID was passed in with the keyword arguments
+        srid = kwargs.get('srid')
+
         ncoords = len(coords)
+        if not ncoords:
+            super(LineString, self).__init__(self._init_func(None), srid=srid)
+            return
+
         if ncoords < self._minlength:
             raise ValueError(
                 '%s requires at least %d points, got %s.' % (
@@ -80,9 +87,6 @@ class LineString(ProjectInterpolateMixin, GEOSGeometry):
             else:
                 cs[i] = coords[i]
 
-        # If SRID was passed in with the keyword arguments
-        srid = kwargs.get('srid')
-
         # Calling the base geometry initialization with the returned pointer
         #  from the function.
         super(LineString, self).__init__(self._init_func(cs.ptr), srid=srid)

django/contrib/gis/geos/mutable_list.py

@@ -229,7 +229,7 @@ class ListMixin(object):
 
     # ### Private routines ###
     def _rebuild(self, newLen, newItems):
-        if newLen < self._minlength:
+        if newLen and newLen < self._minlength:
             raise ValueError('Must have at least %d items' % self._minlength)
         if self._maxlength is not None and newLen > self._maxlength:
             raise ValueError('Cannot have more than %d items' % self._maxlength)

django/contrib/gis/geos/point.py

@@ -14,7 +14,7 @@ class Point(GEOSGeometry):
     _maxlength = 3
     has_cs = True
 
-    def __init__(self, x, y=None, z=None, srid=None):
+    def __init__(self, x=None, y=None, z=None, srid=None):
         """
         The Point object may be initialized with either a tuple, or individual
         parameters.
@@ -23,22 +23,21 @@ class Point(GEOSGeometry):
         >>> p = Point((5, 23)) # 2D point, passed in as a tuple
         >>> p = Point(5, 23, 8) # 3D point, passed in with individual parameters
         """
-        if isinstance(x, (tuple, list)):
+        if x is None:
+            coords = []
+        elif isinstance(x, (tuple, list)):
             # Here a tuple or list was passed in under the `x` parameter.
-            ndim = len(x)
             coords = x
         elif isinstance(x, six.integer_types + (float,)) and isinstance(y, six.integer_types + (float,)):
             # Here X, Y, and (optionally) Z were passed in individually, as parameters.
             if isinstance(z, six.integer_types + (float,)):
-                ndim = 3
                 coords = [x, y, z]
             else:
-                ndim = 2
                 coords = [x, y]
         else:
             raise TypeError('Invalid parameters given for Point initialization.')
 
-        point = self._create_point(ndim, coords)
+        point = self._create_point(len(coords), coords)
 
         # Initializing using the address returned from the GEOS
         #  createPoint factory.
@@ -48,6 +47,9 @@ class Point(GEOSGeometry):
         """
         Create a coordinate sequence, set X, Y, [Z], and create point
         """
+        if not ndim:
+            return capi.create_point(None)
+
         if ndim < 2 or ndim > 3:
             raise TypeError('Invalid point dimension: %s' % str(ndim))
 

django/contrib/gis/geos/polygon.py

@@ -29,7 +29,8 @@ class Polygon(GEOSGeometry):
         ...                ((4, 4), (4, 6), (6, 6), (6, 4), (4, 4)))
         """
         if not args:
-            raise TypeError('Must provide at least one LinearRing, or a tuple, to initialize a Polygon.')
+            super(Polygon, self).__init__(self._create_polygon(0, None), **kwargs)
+            return
 
         # Getting the ext_ring and init_holes parameters from the argument list
         ext_ring = args[0]
@@ -73,6 +74,9 @@ class Polygon(GEOSGeometry):
         # _construct_ring will throw a TypeError if a parameter isn't a valid ring
         # If we cloned the pointers here, we wouldn't be able to clean up
         # in case of error.
+        if not length:
+            return capi.create_empty_polygon()
+
         rings = []
         for r in items:
             if isinstance(r, GEOM_PTR):

django/contrib/gis/geos/prototypes/__init__.py

@@ -9,11 +9,12 @@ from django.contrib.gis.geos.prototypes.coordseq import (  # NOQA
     cs_gety, cs_getz, cs_setordinate, cs_setx, cs_sety, cs_setz, get_cs,
 )
 from django.contrib.gis.geos.prototypes.geom import (  # NOQA
-    create_collection, create_linearring, create_linestring, create_point,
-    create_polygon, destroy_geom, from_hex, from_wkb, from_wkt, geom_clone,
-    geos_get_srid, geos_normalize, geos_set_srid, geos_type, geos_typeid,
-    get_dims, get_extring, get_geomn, get_intring, get_nrings, get_num_coords,
-    get_num_geoms, to_hex, to_wkb, to_wkt,
+    create_collection, create_empty_polygon, create_linearring,
+    create_linestring, create_point, create_polygon, destroy_geom, from_hex,
+    from_wkb, from_wkt, geom_clone, geos_get_srid, geos_normalize,
+    geos_set_srid, geos_type, geos_typeid, get_dims, get_extring, get_geomn,
+    get_intring, get_nrings, get_num_coords, get_num_geoms, to_hex, to_wkb,
+    to_wkt,
 )
 from django.contrib.gis.geos.prototypes.misc import *  # NOQA
 from django.contrib.gis.geos.prototypes.predicates import (  # NOQA

django/contrib/gis/geos/prototypes/geom.py

@@ -94,6 +94,7 @@ create_linearring = GeomOutput('GEOSGeom_createLinearRing', [CS_PTR])
 # Polygon and collection creation routines are special and will not
 # have their argument types defined.
 create_polygon = GeomOutput('GEOSGeom_createPolygon', None)
+create_empty_polygon = GeomOutput('GEOSGeom_createEmptyPolygon', None)
 create_collection = GeomOutput('GEOSGeom_createCollection', None)
 
 # Ring routines