Merge pull request #201 from apollo13/atomic

Use Django's atomic when available.

.travis.yml

 language: python
-
-python:
-  - "2.6"
-  - "2.7"
-  - "3.2"
-  - "3.3"
-
 env:
-  - DJANGO=https://github.com/django/django/archive/master.tar.gz
-  - DJANGO=django==1.6
-  - DJANGO=django==1.5.5
-  - DJANGO=django==1.4.10
-
+  - TOXENV=py27-1.7.x
+  - TOXENV=py33-1.5.x
+  - TOXENV=py27-1.6.x
+  - TOXENV=py33-1.6.x
+  - TOXENV=py26-1.6.x
+  - TOXENV=py27-1.5.x
+  - TOXENV=py27-1.4.x
+  - TOXENV=py33-1.7.x
+  - TOXENV=py26-1.4.x
+  - TOXENV=py26-1.5.x
 install:
-  - pip install $DJANGO
-  - pip install -r requirements/travis-ci.txt --use-mirrors
-
+  - pip install tox
 script:
-  - coverage run --source django_taggit runtests.py
-  - coverage report
-
+  - tox
 notifications:
   email: false
-
-matrix:
-  exclude:
-    - python: "3.2"
-      env: DJANGO=django==1.4.10
-    - python: "3.3"
-      env: DJANGO=django==1.4.10
-    - python: "2.6"
-      env: DJANGO=https://github.com/django/django/archive/master.tar.gz
-

taggit/models.py

@@ -9,6 +9,23 @@ from django.utils.translation import ugettext_lazy as _, ugettext
 from django.utils.encoding import python_2_unicode_compatible
 
 
+try:
+    atomic = transaction.atomic
+except AttributeError:
+    from contextlib import contextmanager
+
+    @contextmanager
+    def atomic(using=None):
+        sid = transaction.savepoint(using=using)
+        try:
+            yield
+        except IntegrityError:
+            transaction.savepoint_rollback(sid, using=using)
+            raise
+        else:
+            transaction.savepoint_commit(sid, using=using)
+
+
 @python_2_unicode_compatible
 class TagBase(models.Model):
     name = models.CharField(verbose_name=_('Name'), unique=True, max_length=100)
@@ -30,17 +47,14 @@ class TagBase(models.Model):
             # with a multi-master setup, theoretically we could try to
             # write and rollback on different DBs
             kwargs["using"] = using
-            trans_kwargs = {"using": using}
             i = 0
             while True:
                 i += 1
                 try:
-                    sid = transaction.savepoint(**trans_kwargs)
-                    res = super(TagBase, self).save(*args, **kwargs)
-                    transaction.savepoint_commit(sid, **trans_kwargs)
+                    with atomic(using=using):
+                        res = super(TagBase, self).save(*args, **kwargs)
                     return res
                 except IntegrityError:
-                    transaction.savepoint_rollback(sid, **trans_kwargs)
                     self.slug = self.slugify(self.name, i)
         else:
             return super(TagBase, self).save(*args, **kwargs)

tox.ini

@@ -58,24 +58,6 @@ deps =
 	{[testenv]deps}
 	{[testenv]deps17}
 
-[testenv:py32-1.5.x]
-basepython = python3.2
-deps =
-	{[testenv]deps}
-	{[testenv]deps15}
-
-[testenv:py32-1.6.x]
-basepython = python3.2
-deps =
-	{[testenv]deps}
-	{[testenv]deps16}
-
-[testenv:py32-1.7.x]
-basepython = python3.2
-deps =
-	{[testenv]deps}
-	{[testenv]deps17}
-
 [testenv:py33-1.5.x]
 basepython = python3.3
 deps =