[1.3.X] Fixed #13648 - '%s' escaping support for sqlite3 regression.

Thanks to master for the report and initial patch, and salgado and others
for work on the patch.

Backport of [16209] from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.3.X@16210 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/backends/sqlite3/base.py

@@ -220,7 +220,7 @@ def close(self):
         if self.settings_dict['NAME'] != ":memory:":
             BaseDatabaseWrapper.close(self)
 
-FORMAT_QMARK_REGEX = re.compile(r'(?![^%])%s')
+FORMAT_QMARK_REGEX = re.compile(r'(?<!%)%s')
 
 class SQLiteCursorWrapper(Database.Cursor):
     """

tests/regressiontests/backends/tests.py

@@ -194,6 +194,20 @@ def receiver(sender, connection, **kwargs):
         self.assertTrue(data == {})
 
 
+class EscapingChecks(TestCase):
+
+    @unittest.skipUnless(connection.vendor == 'sqlite',
+                         "This is a sqlite-specific issue")
+    def test_parameter_escaping(self):
+        #13648: '%s' escaping support for sqlite3
+        cursor = connection.cursor()
+        response = cursor.execute(
+            "select strftime('%%s', date('now'))").fetchall()[0][0]
+        self.assertNotEqual(response, None)
+        # response should be an non-zero integer
+        self.assertTrue(int(response))
+
+
 class BackendTestCase(TestCase):
     def test_cursor_executemany(self):
         #4896: Test cursor.executemany