Fixed #14223 -- Extended unification of exception raised in presence of integrity constraint violations.

The unification had been introduced in r12352 and native backend exceptions still
slipped through in cases that end in connection.commit() call. Thanks Alex,
Jacob and Carl for reviewing.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14320 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/backends/postgresql/base.py

@@ -153,6 +153,13 @@ class DatabaseWrapper(BaseDatabaseWrapper):
             cursor.execute("SET client_encoding to 'UNICODE'")
         return UnicodeCursorWrapper(cursor, 'utf-8')
 
+    def _commit(self):
+        if self.connection is not None:
+            try:
+                return self.connection.commit()
+            except Database.IntegrityError, e:
+                raise utils.IntegrityError, utils.IntegrityError(*tuple(e)), sys.exc_info()[2]
+
 def typecast_string(s):
     """
     Cast all returned strings to unicode strings.

django/db/backends/postgresql_psycopg2/base.py

@@ -192,3 +192,10 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         finally:
             self.isolation_level = level
             self.features.uses_savepoints = bool(level)
+
+    def _commit(self):
+        if self.connection is not None:
+            try:
+                return self.connection.commit()
+            except Database.IntegrityError, e:
+                raise utils.IntegrityError, utils.IntegrityError(*tuple(e)), sys.exc_info()[2]

tests/regressiontests/backends/models.py

@@ -1,8 +1,7 @@
 from django.contrib.contenttypes import generic
 from django.contrib.contenttypes.models import ContentType
-from django.conf import settings
 from django.db import models
-from django.db import connection, DEFAULT_DB_ALIAS
+from django.db import connection
 
 
 class Square(models.Model):
@@ -55,3 +54,18 @@ class Post(models.Model):
         db_table = 'CaseSensitive_Post'
 
 
+class Reporter(models.Model):
+    first_name = models.CharField(max_length=30)
+    last_name = models.CharField(max_length=30)
+
+    def __unicode__(self):
+        return u"%s %s" % (self.first_name, self.last_name)
+
+
+class Article(models.Model):
+    headline = models.CharField(max_length=100)
+    pub_date = models.DateField()
+    reporter = models.ForeignKey(Reporter)
+
+    def __unicode__(self):
+        return self.headline

tests/regressiontests/backends/tests.py

@@ -2,13 +2,11 @@
 # Unit and doctests for specific database backends.
 import datetime
 
-from django.conf import settings
-from django.core import management
 from django.core.management.color import no_style
-from django.db import backend, connection, connections, DEFAULT_DB_ALIAS
+from django.db import backend, connection, connections, DEFAULT_DB_ALIAS, IntegrityError
 from django.db.backends.signals import connection_created
 from django.db.backends.postgresql import version as pg_version
-from django.test import TestCase, skipUnlessDBFeature
+from django.test import TestCase, skipUnlessDBFeature, TransactionTestCase
 from django.utils import unittest
 
 from regressiontests.backends import models
@@ -225,3 +223,43 @@ class BackendTestCase(TestCase):
         self.assertEqual(list(cursor.fetchmany(2)), [(u'Jane', u'Doe'), (u'John', u'Doe')])
         self.assertEqual(list(cursor.fetchall()), [(u'Mary', u'Agnelline'), (u'Peter', u'Parker')])
 
+
+# We don't make these tests conditional because that means we would need to
+# check and differentiate between:
+# * MySQL+InnoDB, MySQL+MYISAM (something we currently can't do).
+# * if sqlite3 (if/once we get #14204 fixed) has referential integrity turned
+#   on or not, something that would be controlled by runtime support and user
+#   preference.
+# verify if its type is django.database.db.IntegrityError.
+
+class FkConstraintsTests(TransactionTestCase):
+
+    def setUp(self):
+        # Create a Reporter.
+        self.r = models.Reporter.objects.create(first_name='John', last_name='Smith')
+
+    def test_integrity_checks_on_creation(self):
+        """
+        Try to create a model instance that violates a FK constraint. If it
+        fails it should fail with IntegrityError.
+        """
+        a = models.Article(headline="This is a test", pub_date=datetime.datetime(2005, 7, 27), reporter_id=30)
+        try:
+            a.save()
+        except IntegrityError:
+            pass
+
+    def test_integrity_checks_on_update(self):
+        """
+        Try to update a model instance introducing a FK constraint violation.
+        If it fails it should fail with IntegrityError.
+        """
+        # Create an Article.
+        models.Article.objects.create(headline="Test article", pub_date=datetime.datetime(2010, 9, 4), reporter=self.r)
+        # Retrive it from the DB
+        a = models.Article.objects.get(headline="Test article")
+        a.reporter_id = 30
+        try:
+            a.save()
+        except IntegrityError:
+            pass