From e7e55059027ae2f644c852e0ba60dc9307b425e1 Mon Sep 17 00:00:00 2001
From: Claude Paroz <claude@2xlibre.net>
Date: Fri, 16 Nov 2018 15:10:33 +0100
Subject: [PATCH] Fixed #29959 -- Cached GEOS version in WKBWriter class.

Regression in f185d929fa1c0caad8c03fccde899b647d7248c6.
---
 django/contrib/gis/geos/prototypes/io.py | 5 +++--
 docs/releases/1.11.17.txt                | 4 +++-
 docs/releases/2.0.10.txt                 | 4 +++-
 docs/releases/2.1.4.txt                  | 4 ++++
 4 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/django/contrib/gis/geos/prototypes/io.py b/django/contrib/gis/geos/prototypes/io.py
index 8660e190f5..4a1180ad7a 100644
--- a/django/contrib/gis/geos/prototypes/io.py
+++ b/django/contrib/gis/geos/prototypes/io.py
@@ -213,6 +213,7 @@ class WKBWriter(IOBase):
     _constructor = wkb_writer_create
     ptr_type = WKB_WRITE_PTR
     destructor = wkb_writer_destroy
+    geos_version = geos_version_tuple()
 
     def __init__(self, dim=2):
         super().__init__()
@@ -235,7 +236,7 @@ class WKBWriter(IOBase):
         from django.contrib.gis.geos import Polygon
         geom = self._handle_empty_point(geom)
         wkb = wkb_writer_write(self.ptr, geom.ptr, byref(c_size_t()))
-        if geos_version_tuple() < (3, 6, 1) and isinstance(geom, Polygon) and geom.empty:
+        if self.geos_version < (3, 6, 1) and isinstance(geom, Polygon) and geom.empty:
             # Fix GEOS output for empty polygon.
             # See https://trac.osgeo.org/geos/ticket/680.
             wkb = wkb[:-8] + b'\0' * 4
@@ -246,7 +247,7 @@ class WKBWriter(IOBase):
         from django.contrib.gis.geos.polygon import Polygon
         geom = self._handle_empty_point(geom)
         wkb = wkb_writer_write_hex(self.ptr, geom.ptr, byref(c_size_t()))
-        if geos_version_tuple() < (3, 6, 1) and isinstance(geom, Polygon) and geom.empty:
+        if self.geos_version < (3, 6, 1) and isinstance(geom, Polygon) and geom.empty:
             wkb = wkb[:-16] + b'0' * 8
         return wkb
 
diff --git a/docs/releases/1.11.17.txt b/docs/releases/1.11.17.txt
index 52d86601a6..db201d0b9a 100644
--- a/docs/releases/1.11.17.txt
+++ b/docs/releases/1.11.17.txt
@@ -9,4 +9,6 @@ Django 1.11.17 fixes several bugs in 1.11.16.
 Bugfixes
 ========
 
-* ...
+* Prevented repetitive calls to ``geos_version_tuple()`` in the ``WKBWriter``
+  class in an attempt to fix a random crash involving ``LooseVersion`` since
+  Django 1.11.14 (:ticket:`29959`).
diff --git a/docs/releases/2.0.10.txt b/docs/releases/2.0.10.txt
index 70d74559a4..fd2e7f5ebf 100644
--- a/docs/releases/2.0.10.txt
+++ b/docs/releases/2.0.10.txt
@@ -9,4 +9,6 @@ Django 2.0.10 fixes several bugs in 2.0.9.
 Bugfixes
 ========
 
-* ...
+* Prevented repetitive calls to ``geos_version_tuple()`` in the ``WKBWriter``
+  class in an attempt to fix a random crash involving ``LooseVersion`` since
+  Django 2.0.6 (:ticket:`29959`).
diff --git a/docs/releases/2.1.4.txt b/docs/releases/2.1.4.txt
index 6f05a04357..82378b16a0 100644
--- a/docs/releases/2.1.4.txt
+++ b/docs/releases/2.1.4.txt
@@ -12,3 +12,7 @@ Bugfixes
 * Corrected the default password list that ``CommonPasswordValidator`` uses by
   lowercasing all passwords to match the format expected by the validator
   (:ticket:`29952`).
+
+* Prevented repetitive calls to ``geos_version_tuple()`` in the ``WKBWriter``
+  class in an attempt to fix a random crash involving ``LooseVersion``
+  (:ticket:`29959`).