Fix/appveyor all (#1)

* Create python-33.yml

* Delete python-33.yml

* Update appveyor.yml

* Update appveyor.yml

* Update appveyor.yml

* Update appveyor.yml

* Update appveyor.yml

* Update appveyor.yml

* Update appveyor.yml

* Update appveyor.yml

* Update appveyor.yml

* Update appveyor.yml

* Update appveyor.yml

* Use weakref for conflicts caching

To prevent GC issues for python <= 3.3, use a weak reference for Index._conflicts

* Update index.py

* Update appveyor.yml

appveyor.yml

@@ -3,16 +3,29 @@ image: Visual Studio 2015
 configuration: Release
 environment:
   matrix:
-  - ARCH: 32
-    GENERATOR: 'Visual Studio 11'
+  - GENERATOR: 'Visual Studio 10'
+    PYTHON: 'C:\Python27\python.exe'
+  - GENERATOR: 'Visual Studio 10 Win64'
+    PYTHON: 'C:\Python27-x64\python.exe'
+  - GENERATOR: 'Visual Studio 10'
+    PYTHON: 'C:\Python32\python.exe'
+  - GENERATOR: 'Visual Studio 10 Win64'
+    PYTHON: 'C:\Python32-x64\python.exe'
+  - GENERATOR: 'Visual Studio 10'
+    PYTHON: 'C:\Python33\python.exe'
+  - GENERATOR: 'Visual Studio 10 Win64'
+    PYTHON: 'C:\Python33-x64\python.exe'
+  - GENERATOR: 'Visual Studio 10'
+    PYTHON: 'C:\Python34\python.exe'
+  - GENERATOR: 'Visual Studio 10 Win64'
+    PYTHON: 'C:\Python34-x64\python.exe'
+  - GENERATOR: 'Visual Studio 14'
     PYTHON: 'C:\Python35\python.exe'
-    PIP: 'C:\Python35\Scripts\pip.exe'
-  - ARCH: 64
-    GENERATOR: 'Visual Studio 11 Win64'
+  - GENERATOR: 'Visual Studio 14 Win64'
     PYTHON: 'C:\Python35-x64\python.exe'
-    PIP: 'C:\Python35-x64\Scripts\pip.exe'
+
 init:
-- cmd: '%PIP% install nose wheel'
+- cmd: '%PYTHON% -m pip install -U nose wheel'
 build_script:
 - cmd: |
     set LIBGIT2=%APPVEYOR_BUILD_FOLDER%\build\libgit2
@@ -24,8 +37,9 @@ build_script:
     cmake --build . --config Release --target install
     cd ..
     
+    IF "%GENERATOR%"=="Visual Studio 10 Win64" ( call "C:\Program Files\Microsoft SDKs\Windows\v7.1\Bin\SetEnv.cmd" )
+    
     "%PYTHON%" setup.py bdist_wheel 
-    "%PIP%" install .
 test_script:
 - ps: |
     cp build\Release\git2.dll .

pygit2/index.py

@@ -28,6 +28,8 @@
 # Import from the future
 from __future__ import absolute_import, unicode_literals
 
+import weakref
+
 # Import from pygit2
 from _pygit2 import Oid, Tree, Diff
 from .errors import check_error
@@ -305,10 +307,12 @@ class Index(object):
             self._conflicts = None
             return None
 
-        if self._conflicts is None:
-            self._conflicts = ConflictCollection(self)
+        if self._conflicts is None or self._conflicts() is None:
+            conflicts = ConflictCollection(self)
+            self._conflicts = weakref.ref(conflicts)
+            return conflicts
 
-        return self._conflicts
+        return self._conflicts()
 
 
 class IndexEntry(object):