Dropped support for GEOS < 3.1

11 files changed, 51 insertions, 121 deletions

diff --git a/django/contrib/gis/geos/__init__.py b/django/contrib/gis/geos/__init__.py
index 70b73fad8b..d5fe479dae 100644
--- a/django/contrib/gis/geos/__init__.py
+++ b/django/contrib/gis/geos/__init__.py
@@ -6,9 +6,9 @@ for more details:
 __all__ = ['HAS_GEOS']
 
 try:
-    from .libgeos import geos_version, geos_version_info, GEOS_PREPARE  # NOQA: flake8 detects only the last __all__
+    from .libgeos import geos_version, geos_version_info  # NOQA: flake8 detects only the last __all__
     HAS_GEOS = True
-    __all__ += ['geos_version', 'geos_version_info', 'GEOS_PREPARE']
+    __all__ += ['geos_version', 'geos_version_info']
 except ImportError:
     HAS_GEOS = False
 
diff --git a/django/contrib/gis/geos/collections.py b/django/contrib/gis/geos/collections.py
index 426cf3833d..483cb6f405 100644
--- a/django/contrib/gis/geos/collections.py
+++ b/django/contrib/gis/geos/collections.py
@@ -3,9 +3,8 @@
  GeometryCollection, MultiPoint, MultiLineString, and MultiPolygon
 """
 from ctypes import c_int, c_uint, byref
-from django.contrib.gis.geos.error import GEOSException
 from django.contrib.gis.geos.geometry import GEOSGeometry
-from django.contrib.gis.geos.libgeos import get_pointer_arr, GEOS_PREPARE
+from django.contrib.gis.geos.libgeos import get_pointer_arr
 from django.contrib.gis.geos.linestring import LineString, LinearRing
 from django.contrib.gis.geos.point import Point
 from django.contrib.gis.geos.polygon import Polygon
@@ -119,10 +118,7 @@ class MultiPolygon(GeometryCollection):
     @property
     def cascaded_union(self):
         "Returns a cascaded union of this MultiPolygon."
-        if GEOS_PREPARE:
-            return GEOSGeometry(capi.geos_cascaded_union(self.ptr), self.srid)
-        else:
-            raise GEOSException('The cascaded union operation requires GEOS 3.1+.')
+        return GEOSGeometry(capi.geos_cascaded_union(self.ptr), self.srid)
 
 # Setting the allowed types here since GeometryCollection is defined before
 # its subclasses.
diff --git a/django/contrib/gis/geos/geometry.py b/django/contrib/gis/geos/geometry.py
index 073415abea..f453f113f7 100644
--- a/django/contrib/gis/geos/geometry.py
+++ b/django/contrib/gis/geos/geometry.py
@@ -17,7 +17,7 @@ from django.contrib.gis.gdal.error import SRSException
 from django.contrib.gis.geos.base import GEOSBase, gdal
 from django.contrib.gis.geos.coordseq import GEOSCoordSeq
 from django.contrib.gis.geos.error import GEOSException, GEOSIndexError
-from django.contrib.gis.geos.libgeos import GEOM_PTR, GEOS_PREPARE
+from django.contrib.gis.geos.libgeos import GEOM_PTR
 
 # All other functions in this module come from the ctypes
 # prototypes module -- which handles all interaction with
@@ -289,8 +289,6 @@ class GEOSGeometry(GEOSBase, ListMixin):
         """
         Returns a string containing the reason for any invalidity.
         """
-        if not GEOS_PREPARE:
-            raise GEOSException('Upgrade GEOS to 3.1 to get validity reason.')
         return capi.geos_isvalidreason(self.ptr).decode()
 
     #### Binary predicates. ####
@@ -411,9 +409,6 @@ class GEOSGeometry(GEOSBase, ListMixin):
         extension of the WKB specification that includes SRID value that are
         a part of this geometry.
         """
-        if self.hasz and not GEOS_PREPARE:
-            # See: http://trac.osgeo.org/geos/ticket/216
-            raise GEOSException('Upgrade GEOS to 3.1 to get valid 3D HEXEWKB.')
         return ewkb_w(3 if self.hasz else 2).write_hex(self)
 
     @property
@@ -443,9 +438,6 @@ class GEOSGeometry(GEOSBase, ListMixin):
         This is an extension of the WKB specification that includes any SRID
         value that are a part of this geometry.
         """
-        if self.hasz and not GEOS_PREPARE:
-            # See: http://trac.osgeo.org/geos/ticket/216
-            raise GEOSException('Upgrade GEOS to 3.1 to get valid 3D EWKB.')
         return ewkb_w(3 if self.hasz else 2).write(self)
 
     @property
@@ -460,10 +452,7 @@ class GEOSGeometry(GEOSBase, ListMixin):
         Returns a PreparedGeometry corresponding to this geometry -- it is
         optimized for the contains, intersects, and covers operations.
         """
-        if GEOS_PREPARE:
-            return PreparedGeometry(self)
-        else:
-            raise GEOSException('GEOS 3.1+ required for prepared geometry support.')
+        return PreparedGeometry(self)
 
     #### GDAL-specific output routines ####
     @property
@@ -707,16 +696,14 @@ from django.contrib.gis.geos.linestring import LineString, LinearRing
 from django.contrib.gis.geos.point import Point
 from django.contrib.gis.geos.polygon import Polygon
 from django.contrib.gis.geos.collections import GeometryCollection, MultiPoint, MultiLineString, MultiPolygon
-GEOS_CLASSES = {0: Point,
-                1: LineString,
-                2: LinearRing,
-                3: Polygon,
-                4: MultiPoint,
-                5: MultiLineString,
-                6: MultiPolygon,
-                7: GeometryCollection,
-                }
-
-# If supported, import the PreparedGeometry class.
-if GEOS_PREPARE:
-    from django.contrib.gis.geos.prepared import PreparedGeometry
+from django.contrib.gis.geos.prepared import PreparedGeometry
+GEOS_CLASSES = {
+    0: Point,
+    1: LineString,
+    2: LinearRing,
+    3: Polygon,
+    4: MultiPoint,
+    5: MultiLineString,
+    6: MultiPolygon,
+    7: GeometryCollection,
+}
diff --git a/django/contrib/gis/geos/libgeos.py b/django/contrib/gis/geos/libgeos.py
index 239067a433..5be05cee50 100644
--- a/django/contrib/gis/geos/libgeos.py
+++ b/django/contrib/gis/geos/libgeos.py
@@ -155,22 +155,10 @@ GEOS_MINOR_VERSION = int(_verinfo['minor'])
 GEOS_SUBMINOR_VERSION = int(_verinfo['subminor'])
 del _verinfo
 GEOS_VERSION = (GEOS_MAJOR_VERSION, GEOS_MINOR_VERSION, GEOS_SUBMINOR_VERSION)
-GEOS_PREPARE = GEOS_VERSION >= (3, 1, 0)
 
-if GEOS_PREPARE:
-    # Here we set up the prototypes for the initGEOS_r and finishGEOS_r
-    # routines.  These functions aren't actually called until they are
-    # attached to a GEOS context handle -- this actually occurs in
-    # geos/prototypes/threadsafe.py.
-    lgeos.initGEOS_r.restype = CONTEXT_PTR
-    lgeos.finishGEOS_r.argtypes = [CONTEXT_PTR]
-else:
-    # When thread-safety isn't available, the initGEOS routine must be called
-    # first.  This function takes the notice and error functions, defined
-    # as Python callbacks above, as parameters. Here is the C code that is
-    # wrapped:
-    #  extern void GEOS_DLL initGEOS(GEOSMessageHandler notice_function, GEOSMessageHandler error_function);
-    lgeos.initGEOS(notice_h, error_h)
-    # Calling finishGEOS() upon exit of the interpreter.
-    import atexit
-    atexit.register(lgeos.finishGEOS)
+# Here we set up the prototypes for the initGEOS_r and finishGEOS_r
+# routines.  These functions aren't actually called until they are
+# attached to a GEOS context handle -- this actually occurs in
+# geos/prototypes/threadsafe.py.
+lgeos.initGEOS_r.restype = CONTEXT_PTR
+lgeos.finishGEOS_r.argtypes = [CONTEXT_PTR]
diff --git a/django/contrib/gis/geos/prototypes/misc.py b/django/contrib/gis/geos/prototypes/misc.py
index 6b10396aba..a8bb3cbd58 100644
--- a/django/contrib/gis/geos/prototypes/misc.py
+++ b/django/contrib/gis/geos/prototypes/misc.py
@@ -3,13 +3,13 @@
  ones that return the area, distance, and length.
 """
 from ctypes import c_int, c_double, POINTER
-from django.contrib.gis.geos.libgeos import GEOM_PTR, GEOS_PREPARE
+from django.contrib.gis.geos.libgeos import GEOM_PTR
 from django.contrib.gis.geos.prototypes.errcheck import check_dbl, check_string
 from django.contrib.gis.geos.prototypes.geom import geos_char_p
 from django.contrib.gis.geos.prototypes.threadsafe import GEOSFunc
 from django.utils.six.moves import xrange
 
-__all__ = ['geos_area', 'geos_distance', 'geos_length']
+__all__ = ['geos_area', 'geos_distance', 'geos_length', 'geos_isvalidreason']
 
 
 ### ctypes generator function ###
@@ -31,11 +31,7 @@ def dbl_from_geom(func, num_geom=1):
 geos_area = dbl_from_geom(GEOSFunc('GEOSArea'))
 geos_distance = dbl_from_geom(GEOSFunc('GEOSDistance'), num_geom=2)
 geos_length = dbl_from_geom(GEOSFunc('GEOSLength'))
-
-# Validity reason; only in GEOS 3.1+
-if GEOS_PREPARE:
-    geos_isvalidreason = GEOSFunc('GEOSisValidReason')
-    geos_isvalidreason.argtypes = [GEOM_PTR]
-    geos_isvalidreason.restype = geos_char_p
-    geos_isvalidreason.errcheck = check_string
-    __all__.append('geos_isvalidreason')
+geos_isvalidreason = GEOSFunc('GEOSisValidReason')
+geos_isvalidreason.argtypes = [GEOM_PTR]
+geos_isvalidreason.restype = geos_char_p
+geos_isvalidreason.errcheck = check_string
diff --git a/django/contrib/gis/geos/prototypes/topology.py b/django/contrib/gis/geos/prototypes/topology.py
index 5bc99e8409..60db46ec14 100644
--- a/django/contrib/gis/geos/prototypes/topology.py
+++ b/django/contrib/gis/geos/prototypes/topology.py
@@ -2,13 +2,14 @@
  This module houses the GEOS ctypes prototype functions for the
  topological operations on geometries.
 """
-__all__ = ['geos_boundary', 'geos_buffer', 'geos_centroid', 'geos_convexhull',
-           'geos_difference', 'geos_envelope', 'geos_intersection',
-           'geos_linemerge', 'geos_pointonsurface', 'geos_preservesimplify',
-           'geos_simplify', 'geos_symdifference', 'geos_union', 'geos_relate']
+__all__ = ['geos_boundary', 'geos_buffer', 'geos_cascaded_union',
+           'geos_centroid', 'geos_convexhull', 'geos_difference',
+           'geos_envelope', 'geos_intersection', 'geos_linemerge',
+           'geos_pointonsurface', 'geos_preservesimplify', 'geos_simplify',
+           'geos_symdifference', 'geos_union', 'geos_relate']
 
 from ctypes import c_double, c_int
-from django.contrib.gis.geos.libgeos import geos_version_info, GEOM_PTR, GEOS_PREPARE
+from django.contrib.gis.geos.libgeos import geos_version_info, GEOM_PTR
 from django.contrib.gis.geos.prototypes.errcheck import check_geom, check_minus_one, check_string
 from django.contrib.gis.geos.prototypes.geom import geos_char_p
 from django.contrib.gis.geos.prototypes.threadsafe import GEOSFunc
@@ -39,19 +40,16 @@ geos_simplify = topology(GEOSFunc('GEOSSimplify'), c_double)
 geos_symdifference = topology(GEOSFunc('GEOSSymDifference'), GEOM_PTR)
 geos_union = topology(GEOSFunc('GEOSUnion'), GEOM_PTR)
 
+geos_cascaded_union = GEOSFunc('GEOSUnionCascaded')
+geos_cascaded_union.argtypes = [GEOM_PTR]
+geos_cascaded_union.restype = GEOM_PTR
+
 # GEOSRelate returns a string, not a geometry.
 geos_relate = GEOSFunc('GEOSRelate')
 geos_relate.argtypes = [GEOM_PTR, GEOM_PTR]
 geos_relate.restype = geos_char_p
 geos_relate.errcheck = check_string
 
-# Routines only in GEOS 3.1+
-if GEOS_PREPARE:
-    geos_cascaded_union = GEOSFunc('GEOSUnionCascaded')
-    geos_cascaded_union.argtypes = [GEOM_PTR]
-    geos_cascaded_union.restype = GEOM_PTR
-    __all__.append('geos_cascaded_union')
-
 # Linear referencing routines
 info = geos_version_info()
 if info['version'] >= '3.2.0':
diff --git a/django/contrib/gis/geos/tests/test_geos.py b/django/contrib/gis/geos/tests/test_geos.py
index 9ce7e0d73d..8356343839 100644
--- a/django/contrib/gis/geos/tests/test_geos.py
+++ b/django/contrib/gis/geos/tests/test_geos.py
@@ -22,8 +22,7 @@ from .. import HAS_GEOS
 if HAS_GEOS:
     from .. import (GEOSException, GEOSIndexError, GEOSGeometry,
         GeometryCollection, Point, MultiPoint, Polygon, MultiPolygon, LinearRing,
-        LineString, MultiLineString, fromfile, fromstr, geos_version_info,
-        GEOS_PREPARE)
+        LineString, MultiLineString, fromfile, fromstr, geos_version_info)
     from ..base import gdal, numpy, GEOSBase
 
 
@@ -121,20 +120,12 @@ class GEOSTest(unittest.TestCase, TestDataMixin):
         # a bug in versions prior to 3.1 that puts the X coordinate in
         # place of Z; an exception should be raised on those versions.
         self.assertEqual(hexewkb_2d, pnt_2d.hexewkb)
-        if GEOS_PREPARE:
-            self.assertEqual(hexewkb_3d, pnt_3d.hexewkb)
-            self.assertEqual(True, GEOSGeometry(hexewkb_3d).hasz)
-        else:
-            with self.assertRaises(GEOSException):
-                pnt_3d.hexewkb
+        self.assertEqual(hexewkb_3d, pnt_3d.hexewkb)
+        self.assertEqual(True, GEOSGeometry(hexewkb_3d).hasz)
 
         # Same for EWKB.
         self.assertEqual(memoryview(a2b_hex(hexewkb_2d)), pnt_2d.ewkb)
-        if GEOS_PREPARE:
-            self.assertEqual(memoryview(a2b_hex(hexewkb_3d)), pnt_3d.ewkb)
-        else:
-            with self.assertRaises(GEOSException):
-                pnt_3d.ewkb
+        self.assertEqual(memoryview(a2b_hex(hexewkb_3d)), pnt_3d.ewkb)
 
         # Redundant sanity check.
         self.assertEqual(4326, GEOSGeometry(hexewkb_2d).srid)
@@ -869,10 +860,9 @@ class GEOSTest(unittest.TestCase, TestDataMixin):
         self.assertIsInstance(g1.ogr, gdal.OGRGeometry)
         self.assertIsNone(g1.srs)
 
-        if GEOS_PREPARE:
-            g1_3d = fromstr('POINT(5 23 8)')
-            self.assertIsInstance(g1_3d.ogr, gdal.OGRGeometry)
-            self.assertEqual(g1_3d.ogr.z, 8)
+        g1_3d = fromstr('POINT(5 23 8)')
+        self.assertIsInstance(g1_3d.ogr, gdal.OGRGeometry)
+        self.assertEqual(g1_3d.ogr.z, 8)
 
         g2 = fromstr('LINESTRING(0 0, 5 5, 23 23)', srid=4326)
         self.assertIsInstance(g2.ogr, gdal.OGRGeometry)
@@ -918,10 +908,7 @@ class GEOSTest(unittest.TestCase, TestDataMixin):
     def test_transform_3d(self):
         p3d = GEOSGeometry('POINT (5 23 100)', 4326)
         p3d.transform(2774)
-        if GEOS_PREPARE:
-            self.assertEqual(p3d.z, 100)
-        else:
-            self.assertIsNone(p3d.z)
+        self.assertEqual(p3d.z, 100)
 
     @skipUnless(HAS_GDAL, "GDAL is required.")
     def test_transform_noop(self):
@@ -1030,7 +1017,6 @@ class GEOSTest(unittest.TestCase, TestDataMixin):
                 if not no_srid:
                     self.assertEqual(geom.srid, tmpg.srid)
 
-    @skipUnless(HAS_GEOS and GEOS_PREPARE, "geos >= 3.1.0 is required")
     def test_prepared(self):
         "Testing PreparedGeometry support."
         # Creating a simple multipolygon and getting a prepared version.
@@ -1061,7 +1047,6 @@ class GEOSTest(unittest.TestCase, TestDataMixin):
         for geom, merged in zip(ref_geoms, ref_merged):
             self.assertEqual(merged, geom.merged)
 
-    @skipUnless(HAS_GEOS and GEOS_PREPARE, "geos >= 3.1.0 is required")
     def test_valid_reason(self):
         "Testing IsValidReason support"
 
diff --git a/docs/ref/contrib/gis/geos.txt b/docs/ref/contrib/gis/geos.txt
index d557af96a3..a1f92b31c7 100644
--- a/docs/ref/contrib/gis/geos.txt
+++ b/docs/ref/contrib/gis/geos.txt
@@ -282,10 +282,6 @@ Returns the EWKB of this Geometry in hexadecimal form.  This is an
 extension of the WKB specification that includes the SRID value
 that are a part of this geometry.
 
-.. note::
-
-   GEOS 3.1 is *required* if you want valid 3D HEXEWKB.
-
 .. attribute:: GEOSGeometry.json
 
 Returns the GeoJSON representation of the geometry.
@@ -329,10 +325,6 @@ Return the EWKB representation of this Geometry as a Python buffer.
 This is an extension of the WKB specification that includes any SRID
 value that are a part of this geometry.
 
-.. note::
-
-   GEOS 3.1 is *required* if you want valid 3D EWKB.
-
 .. attribute:: GEOSGeometry.wkt
 
 Returns the Well-Known Text of the geometry (an OGC standard).
@@ -533,10 +525,6 @@ a :class:`Polygon`).
 
 .. attribute:: GEOSGeometry.prepared
 
-.. note::
-
-    Support for prepared geometries requires GEOS 3.1.
-
 Returns a GEOS ``PreparedGeometry`` for the contents of this geometry.
 ``PreparedGeometry`` objects are optimized for the contains, intersects,
 and covers operations.  Refer to the :ref:`prepared-geometries` documentation
@@ -710,10 +698,6 @@ Geometry Collections
    more efficient (faster) than trying to union the geometries together
    individually. [#fncascadedunion]_
 
-   .. note::
-
-       GEOS 3.1 is *required* to peform cascaded unions.
-
 ``GeometryCollection``
 ----------------------
 
@@ -740,10 +724,6 @@ geometry can be orders of magnitude faster -- the more complex the geometry
 that is prepared, the larger the speedup in the operation.  For more information,
 please consult the `GEOS wiki page on prepared geometries <http://trac.osgeo.org/geos/wiki/PreparedGeometry>`_.
 
-.. note::
-
-   GEOS 3.1 is *required* in order to use prepared geometries.
-
 For example::
 
     >>> from django.contrib.gis.geos import Point, Polygon
diff --git a/docs/ref/contrib/gis/install/geolibs.txt b/docs/ref/contrib/gis/install/geolibs.txt
index 508bf7809c..a529a497d2 100644
--- a/docs/ref/contrib/gis/install/geolibs.txt
+++ b/docs/ref/contrib/gis/install/geolibs.txt
@@ -10,7 +10,7 @@ geospatial libraries:
 ========================  ====================================  ================================  ==========================
 Program                   Description                           Required                          Supported Versions
 ========================  ====================================  ================================  ==========================
-:ref:`GEOS <ref-geos>`    Geometry Engine Open Source           Yes                               3.3, 3.2, 3.1, 3.0
+:ref:`GEOS <ref-geos>`    Geometry Engine Open Source           Yes                               3.3, 3.2, 3.1
 `PROJ.4`_                 Cartographic Projections library      Yes (PostgreSQL and SQLite only)  4.8, 4.7, 4.6, 4.5, 4.4
 :ref:`GDAL <ref-gdal>`    Geospatial Data Abstraction Library   No (but, required for SQLite)     1.9, 1.8, 1.7, 1.6
 :ref:`GeoIP <ref-geoip>`  IP-based geolocation library          No                                1.4
@@ -20,7 +20,6 @@ Program                   Description                           Required
 
 ..
     Libs release dates:
-    GEOS 3.0.0 2008-08-14
     GEOS 3.1.0 2009-03-11
     GEOS 3.2.0 2009-12-14
     GEOS 3.3.0 2011-05-30
diff --git a/docs/ref/contrib/gis/model-api.txt b/docs/ref/contrib/gis/model-api.txt
index 81b619e338..10cc2957d8 100644
--- a/docs/ref/contrib/gis/model-api.txt
+++ b/docs/ref/contrib/gis/model-api.txt
@@ -172,8 +172,7 @@ three-dimensonal support.
 
 .. note::
 
-    At this time 3D support requires that GEOS 3.1 be installed, and is
-    limited only to the PostGIS spatial backend.
+    At this time 3D support is limited to the PostGIS spatial backend.
 
 ``geography``
 -------------
diff --git a/docs/releases/1.7.txt b/docs/releases/1.7.txt
index 3a1568fe45..21449b4e7c 100644
--- a/docs/releases/1.7.txt
+++ b/docs/releases/1.7.txt
@@ -722,6 +722,8 @@ Miscellaneous
   ``select_related('foo').select_related('bar')``. Previously the latter would
   have been equivalent to ``select_related('bar')``.
 
+* GeoDjango dropped support for GEOS < 3.1.
+
 Features deprecated in 1.7
 ==========================