4 files changed, 72 insertions, 6 deletions
diff --git a/django/db/backends/postgresql/base.py b/django/db/backends/postgresql/base.py
index 5e47a37d3f..12631785bc 100644
--- a/django/db/backends/postgresql/base.py
+++ b/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.
diff --git a/django/db/backends/postgresql_psycopg2/base.py b/django/db/backends/postgresql_psycopg2/base.py
index 9e5fb53d56..71ec58153a 100644
--- a/django/db/backends/postgresql_psycopg2/base.py
+++ b/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]
diff --git a/tests/regressiontests/backends/models.py b/tests/regressiontests/backends/models.py
index 3ad4a60c02..89e3fd27ff 100644
--- a/tests/regressiontests/backends/models.py
+++ b/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
diff --git a/tests/regressiontests/backends/tests.py b/tests/regressiontests/backends/tests.py
index c5d13285d3..e457629880 100644
--- a/tests/regressiontests/backends/tests.py
+++ b/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