Dropped quirks in connection arguments handling

Now connect() raises an exception instead of swallowing keyword arguments
when a connection string is specified as well

Closes ticket #131.

NEWS

@@ -13,6 +13,8 @@ What's new in psycopg 2.4.6
     Thanks to Manu Cupcic for the report (ticket #110).
   - 'register_hstore()', 'register_composite()', 'tpc_recover()' work with
     RealDictConnection and Cursor (ticket #114).
+  - connect() raises an exception instead of swallowing keyword arguments
+    when a connection string is specified as well (ticket #131).
   - 'errorcodes' map updated to PostgreSQL 9.2.
 
 

lib/__init__.py

@@ -146,37 +146,37 @@ def connect(dsn=None,
     Using *async*=True an asynchronous connection will be created.
 
     Any other keyword parameter will be passed to the underlying client
-    library: the list of supported parameter depends on the library version.
+    library: the list of supported parameters depends on the library version.
 
     """
+    items = []
+    if database is not None:
+        items.append(('dbname', database))
+    if user is not None:
+        items.append(('user', user))
+    if password is not None:
+        items.append(('password', password))
+    if host is not None:
+        items.append(('host', host))
+    if port is not None:
+        items.append(('port', port))
+
+    items.extend([(k, v) for (k, v) in kwargs.iteritems() if v is not None])
+
+    if dsn is not None and items:
+        raise InterfaceError(
+            "you cannot specify keyword arguments (%s)"
+            " together with a connection string"
+            % ", ".join([k for k, v in items]))
+
     if dsn is None:
-        # Note: reproducing the behaviour of the previous C implementation:
+        if not items:
-        # keyword are silently swallowed if a DSN is specified. I would have
-        # raised an exception. File under "histerical raisins".
-        items = []
-        if database is not None:
-            items.append(('dbname', database))
-        if user is not None:
-            items.append(('user', user))
-        if password is not None:
-            items.append(('password', password))
-        if host is not None:
-            items.append(('host', host))
-        # Reproducing the previous C implementation behaviour: swallow a
-        # negative port. The libpq would raise an exception for it.
-        if port is not None and int(port) > 0:
-            items.append(('port', port))
-
-        items.extend(
-            [(k, v) for (k, v) in kwargs.iteritems() if v is not None])
-        dsn = " ".join(["%s=%s" % (k, _param_escape(str(v)))
-            for (k, v) in items])
-
-        if not dsn:
             raise InterfaceError('missing dsn and no parameters')
+        else:
+            dsn = " ".join(["%s=%s" % (k, _param_escape(str(v)))
+                for (k, v) in items])
 
-    return _connect(dsn,
+    return _connect(dsn, connection_factory=connection_factory, async=async)
-        connection_factory=connection_factory, async=async)
 
 
 __all__ = filter(lambda k: not k.startswith('_'), locals().keys())

tests/test_module.py

@@ -127,6 +127,14 @@ class ConnectTestCase(unittest.TestCase):
         psycopg2.connect(database=r"\every thing'")
         self.assertEqual(self.args[0], r"dbname='\\every thing\''")
 
+    def test_no_kwargs_swallow(self):
+        self.assertRaises(psycopg2.InterfaceError,
+            psycopg2.connect, 'dbname=foo', database='foo')
+        self.assertRaises(psycopg2.InterfaceError,
+            psycopg2.connect, 'dbname=foo', user='postgres')
+        self.assertRaises(psycopg2.InterfaceError,
+            psycopg2.connect, 'dbname=foo', no_such_param='meh')
+
 
 class ExceptionsTestCase(unittest.TestCase):
     def setUp(self):