Fixes for several tests in test_bool (#261)

* Fixes for several tests in test_bool

* Merge in from IronLanguages/main#1332

Src/IronPython/Runtime/Binding/PythonProtocol.cs

@@ -108,7 +108,21 @@ static partial class PythonProtocol {
                 );
             }
 
-            return Ast.NotEqual(callAsInt, AstUtils.Constant(0));
+            var res = Expression.Parameter(typeof(int));
+            return Ast.Block(
+                new[] { res },
+                Ast.Assign(res, callAsInt),
+                Ast.IfThen(Ast.LessThan(res, Ast.Constant(0)),
+                    Ast.Throw(
+                        Ast.Call(
+                            typeof(PythonOps).GetMethod("ValueError"),
+                            Ast.Constant("__len__() should return >= 0"),
+                            Ast.NewArrayInit(typeof(object))
+                        )
+                    )                    
+                ),
+                Ast.NotEqual(res, Ast.Constant(0))
+            );
         }
 
         #endregion

Src/IronPython/Runtime/Operations/MarshalOps.cs

@@ -81,8 +81,8 @@ private class MarshalWriter {
                 infinite.Add (o);
                 try {
                     if (o == null) _bytes.Add ((byte)'N');
-                    else if (o == ScriptingRuntimeHelpers.True) _bytes.Add ((byte)'T');
-                    else if (o == ScriptingRuntimeHelpers.False) _bytes.Add ((byte)'F');
+                    else if (o == ScriptingRuntimeHelpers.True || (o is bool && (bool)o)) _bytes.Add ((byte)'T');
+                    else if (o == ScriptingRuntimeHelpers.False || (o is bool && (!(bool)o))) _bytes.Add ((byte)'F');
                     else if (o is string) WriteString (o as string);
                     else if (o is int) WriteInt ((int)o);
                     else if (o is float) WriteFloat ((float)o);

Src/IronPython/Runtime/Operations/PythonOps.cs

@@ -470,19 +470,26 @@ public static partial class PythonOps {
         }
 
         public static object Is(object x, object y) {
-            return x == y ? ScriptingRuntimeHelpers.True : ScriptingRuntimeHelpers.False;
+           return IsRetBool(x, y) ? ScriptingRuntimeHelpers.True : ScriptingRuntimeHelpers.False;
         }
 
         public static bool IsRetBool(object x, object y) {
-            return x == y;
-        }
+            if (x == y)
+                return true;
 
-        public static object IsNot(object x, object y) {
-            return x != y ? ScriptingRuntimeHelpers.True : ScriptingRuntimeHelpers.False;
+            // Special case "is True"/"is False" checks. They are somewhat common in 
+            // Python (particularly in tests), but non-Python code may not stick to the
+            // convention of only using the two singleton instances at ScriptingRuntimeHelpers.
+            // (https://github.com/IronLanguages/main/issues/1299)
+            var xb = x as bool?;
+            if (xb.HasValue)
+                return xb == (y as bool?);
+
+            return false;
         }
 
-        public static bool IsNotRetBool(object x, object y) {
-            return x != y;
+        public static object IsNot(object x, object y) {
+            return IsRetBool(x, y) ? ScriptingRuntimeHelpers.False : ScriptingRuntimeHelpers.True;
         }
 
         internal delegate T MultiplySequenceWorker<T>(T self, int count);
@@ -839,7 +846,7 @@ public static partial class PythonOps {
             }
 
             if (res < 0) {
-                throw PythonOps.ValueError("__len__ should return >= 0, got {0}", res);
+                throw PythonOps.ValueError("__len__() should return >= 0");
             }
             return res;
         }

Tests/test_is.py

@@ -0,0 +1,46 @@
+#####################################################################################
+#
+#  Copyright (c) Microsoft Corporation. All rights reserved.
+#
+# This source code is subject to terms and conditions of the Apache License, Version 2.0. A
+# copy of the license can be found in the License.html file at the root of this distribution. If
+# you cannot locate the  Apache License, Version 2.0, please send an email to
+# ironpy@microsoft.com. By using this source code in any fashion, you are agreeing to be bound
+# by the terms of the Apache License, Version 2.0.
+#
+# You must not remove this notice, or any other, from this software.
+#
+#
+#####################################################################################
+
+from iptest.assert_util import *
+
+from System import Nullable
+
+def test_object():
+    a = object()
+    b = object()
+
+    AssertEqual(True, a is a)
+    AssertEqual(False, a is b)
+    AssertEqual(False, a is not a)
+    AssertEqual(True, a is not b)
+
+def test_bool_nullablebool():
+    tc = [
+        # (a, b, a is b)
+        (True, True, True), 
+        (True, False, False), 
+        (Nullable[bool](True), True, True), # https://github.com/IronLanguages/main/issues/1299
+        (Nullable[bool](True), False, False),
+        (Nullable[bool](False), True, False), # dito
+        (Nullable[bool](False), False, True),
+        (None, True, False), 
+        (None, False, False),
+        ]
+
+    for a, b, result in tc:
+        AssertEqual(result, a is b)
+        AssertEqual(result, b is a)
+        AssertEqual(not result, a is not b)
+        AssertEqual(not result, b is not a)