From 5d741c16662cde063e6930e7d3fe87b00ae9b8bb Mon Sep 17 00:00:00 2001
From: Ryan Leckey <rleckey@concordusapps.com>
Date: Wed, 28 May 2014 19:56:19 -0700
Subject: [PATCH] Various fixes for bugs found in use of psycopg2.

---
 sqlalchemy_utils/functions/database.py | 29 ++++++++++++++++++++++----
 sqlalchemy_utils/types/password.py     |  2 +-
 sqlalchemy_utils/types/uuid.py         |  9 ++++----
 3 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/sqlalchemy_utils/functions/database.py b/sqlalchemy_utils/functions/database.py
index 5986cc3..0cfbc6a 100644
--- a/sqlalchemy_utils/functions/database.py
+++ b/sqlalchemy_utils/functions/database.py
@@ -76,7 +76,10 @@ def database_exists(url):
 
     url = copy(make_url(url))
     database = url.database
-    url.database = None
+    if url.drivername.startswith('postgresql'):
+        url.database = 'template1'
+    else:
+        url.database = None
 
     engine = sa.create_engine(url)
 
@@ -126,7 +129,10 @@ def create_database(url, encoding='utf8'):
     url = copy(make_url(url))
 
     database = url.database
-    if not url.drivername.startswith('sqlite'):
+
+    if url.drivername.startswith('postgresql'):
+        url.database = 'template1'
+    elif not url.drivername.startswith('sqlite'):
         url.database = None
 
     engine = sa.create_engine(url)
@@ -137,7 +143,8 @@ def create_database(url, encoding='utf8'):
             engine.raw_connection().set_isolation_level(
                 ISOLATION_LEVEL_AUTOCOMMIT)
 
-        text = "CREATE DATABASE %s ENCODING = '%s'" % (database, encoding)
+        text = "CREATE DATABASE %s ENCODING '%s' TEMPLATE template0" % (
+            database, encoding)
         engine.execute(text)
 
     elif engine.dialect.name == 'mysql':
@@ -168,7 +175,10 @@ def drop_database(url):
     url = copy(make_url(url))
 
     database = url.database
-    if not url.drivername.startswith('sqlite'):
+
+    if url.drivername.startswith('postgresql'):
+        url.database = 'template1'
+    elif not url.drivername.startswith('sqlite'):
         url.database = None
 
     engine = sa.create_engine(url)
@@ -179,6 +189,17 @@ def drop_database(url):
     elif engine.dialect.name == 'postgresql' and engine.driver == 'psycopg2':
         from psycopg2.extensions import ISOLATION_LEVEL_AUTOCOMMIT
         engine.raw_connection().set_isolation_level(ISOLATION_LEVEL_AUTOCOMMIT)
+
+        # Disconnect all users from the database we are dropping.
+        text = '''
+        SELECT pg_terminate_backend(pg_stat_activity.pid)
+        FROM pg_stat_activity
+        WHERE pg_stat_activity.datname = '%s'
+          AND pid <> pg_backend_pid()
+        ''' % database
+        engine.execute(text)
+
+        # Drop the database.
         text = "DROP DATABASE %s" % database
         engine.execute(text)
 
diff --git a/sqlalchemy_utils/types/password.py b/sqlalchemy_utils/types/password.py
index 6820d24..d8034e4 100644
--- a/sqlalchemy_utils/types/password.py
+++ b/sqlalchemy_utils/types/password.py
@@ -143,7 +143,7 @@ class PasswordType(types.TypeDecorator, ScalarCoercible):
             scheme = getattr(__import__('passlib.hash').hash, name)
             length = 4 + len(scheme.name)
             length += len(str(getattr(scheme, 'max_rounds', '')))
-            length += getattr(scheme, 'max_salt_size', 0)
+            length += (getattr(scheme, 'max_salt_size', 0) or 0)
             length += getattr(
                 scheme,
                 'encoded_checksum_size',
diff --git a/sqlalchemy_utils/types/uuid.py b/sqlalchemy_utils/types/uuid.py
index 331eda6..59d29e3 100644
--- a/sqlalchemy_utils/types/uuid.py
+++ b/sqlalchemy_utils/types/uuid.py
@@ -25,14 +25,15 @@ class UUIDType(types.TypeDecorator, ScalarCoercible):
 
     python_type = uuid.UUID
 
-    def __init__(self, binary=True):
+    def __init__(self, binary=True, native=True):
         """
         :param binary: Whether to use a BINARY(16) or CHAR(32) fallback.
         """
         self.binary = binary
+        self.native = native
 
     def load_dialect_impl(self, dialect):
-        if dialect.name == 'postgresql':
+        if dialect.name == 'postgresql' and self.native:
             # Use the native UUID type.
             return dialect.type_descriptor(postgresql.UUID())
 
@@ -59,7 +60,7 @@ class UUIDType(types.TypeDecorator, ScalarCoercible):
         if not isinstance(value, uuid.UUID):
             value = self._coerce(value)
 
-        if dialect.name == 'postgresql':
+        if self.native and dialect.name == 'postgresql':
             return str(value)
 
         return value.bytes if self.binary else value.hex
@@ -68,7 +69,7 @@ class UUIDType(types.TypeDecorator, ScalarCoercible):
         if value is None:
             return value
 
-        if dialect.name == 'postgresql':
+        if self.native and dialect.name == 'postgresql':
             return uuid.UUID(value)
 
         return uuid.UUID(bytes=value) if self.binary else uuid.UUID(value)