From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Tue, 6 Apr 2010 15:39:09 +0000 (-0400)
Subject: - Fixed an error in expression typing which caused an endless
X-Git-Tag: rel_0_6_0~48^2~2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=67878d13ed95a1caafd9d304c916a3abf0320fb6;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

- Fixed an error in expression typing which caused an endless
loop for expressions with two NULL types.
---

diff --git a/CHANGES b/CHANGES
index cdc860b375..2b2b8bd346 100644
--- a/CHANGES
+++ b/CHANGES
@@ -63,6 +63,9 @@ CHANGES
     This includes SQLite, Oracle, Sybase, MS-SQL.
     [ticket:1759]
 
+  - Fixed an error in expression typing which caused an endless
+    loop for expressions with two NULL types.
+    
 - ext
   - the compiler extension now allows @compiles decorators
     on base classes that extend to child classes, @compiles
diff --git a/lib/sqlalchemy/types.py b/lib/sqlalchemy/types.py
index dba75b36e2..198835562f 100644
--- a/lib/sqlalchemy/types.py
+++ b/lib/sqlalchemy/types.py
@@ -524,7 +524,7 @@ class NullType(TypeEngine):
     __visit_name__ = 'null'
 
     def _adapt_expression(self, op, othertype):
-        if othertype is NullType or not operators.is_commutative(op):
+        if othertype is NULLTYPE or not operators.is_commutative(op):
             return op, self
         else:
             return othertype._adapt_expression(op, self)
diff --git a/test/sql/test_types.py b/test/sql/test_types.py
index 2186d47d20..fb9b3912ad 100644
--- a/test/sql/test_types.py
+++ b/test/sql/test_types.py
@@ -884,6 +884,9 @@ class ExpressionTest(TestBase, AssertsExecutionResults, AssertsCompiledSQL):
         expr = column('bar', Integer) - 3
         
         eq_(expr.type._type_affinity, Integer)
+
+        expr = bindparam('bar') + bindparam('foo')
+        eq_(expr.type, types.NULLTYPE)
         
     def test_distinct(self):
         s = select([distinct(test_table.c.avalue)])
@@ -894,6 +897,7 @@ class ExpressionTest(TestBase, AssertsExecutionResults, AssertsCompiledSQL):
 
         assert distinct(test_table.c.data).type == test_table.c.data.type
         assert test_table.c.data.distinct().type == test_table.c.data.type
+    
 
 class DateTest(TestBase, AssertsExecutionResults):
     @classmethod