From b536ad09cadc087b7559db2f8cca50f06c6e8f34 Mon Sep 17 00:00:00 2001
From: Claude Paroz <claude@2xlibre.net>
Date: Tue, 24 Dec 2013 15:19:25 +0100
Subject: [PATCH] [1.6.x] Fixed #21662 -- Kept parent reference in prepared
 geometry

Thanks Robert Scott for the report.
Backport of 542198c1d0 from master.
---
 django/contrib/gis/geos/prepared.py        | 7 ++++++-
 django/contrib/gis/geos/tests/test_geos.py | 4 ++++
 docs/releases/1.6.2.txt                    | 3 ++-
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/django/contrib/gis/geos/prepared.py b/django/contrib/gis/geos/prepared.py
index 68b812df8aa..ae2548ff983 100644
--- a/django/contrib/gis/geos/prepared.py
+++ b/django/contrib/gis/geos/prepared.py
@@ -11,7 +11,12 @@ class PreparedGeometry(GEOSBase):
     ptr_type = capi.PREPGEOM_PTR
 
     def __init__(self, geom):
-        if not isinstance(geom, GEOSGeometry): raise TypeError
+        # Keeping a reference to the original geometry object to prevent it
+        # from being garbage collected which could then crash the prepared one
+        # See #21662
+        self._base_geom = geom
+        if not isinstance(geom, GEOSGeometry):
+            raise TypeError
         self.ptr = capi.geos_prepare(geom.ptr)
 
     def __del__(self):
diff --git a/django/contrib/gis/geos/tests/test_geos.py b/django/contrib/gis/geos/tests/test_geos.py
index c7fe5b23213..c8e064bb956 100644
--- a/django/contrib/gis/geos/tests/test_geos.py
+++ b/django/contrib/gis/geos/tests/test_geos.py
@@ -1043,6 +1043,10 @@ class GEOSTest(unittest.TestCase, TestDataMixin):
             self.assertEqual(mpoly.intersects(pnt), prep.intersects(pnt))
             self.assertEqual(c, prep.covers(pnt))
 
+        # Original geometry deletion should not crash the prepared one (#21662)
+        del mpoly
+        self.assertTrue(prep.covers(Point(5, 5)))
+
     def test_line_merge(self):
         "Testing line merge support"
         ref_geoms = (fromstr('LINESTRING(1 1, 1 1, 3 3)'),
diff --git a/docs/releases/1.6.2.txt b/docs/releases/1.6.2.txt
index cae18b86fa4..fa8bd5bc938 100644
--- a/docs/releases/1.6.2.txt
+++ b/docs/releases/1.6.2.txt
@@ -9,4 +9,5 @@ This is Django 1.6.2, a bugfix release for Django 1.6.
 Bug fixes
 =========
 
-...
+* Prevented the base geometry object of a prepared geometry to be garbage
+  collected, which could lead to crash Django (#21662).