Merge pull request #756 from smourier/master

den-run-ai · web-flow · commit 2857071a4bd6 · 2018-10-29T08:26:53.000-05:00
Inheritance not working with non-abstract base methods
diff --git a/AUTHORS.md b/AUTHORS.md
@@ -42,6 +42,7 @@
 -   Sam Winstanley ([@swinstanley](https://github.com/swinstanley))
 -   Sean Freitag ([@cowboygneox](https://github.com/cowboygneox))
 -   Serge Weinstock ([@sweinst](https://github.com/sweinst))
+-   Simon Mourier ([@smourier](https://github.com/smourier))
 -   Viktoria Kovescses ([@vkovec](https://github.com/vkovec))
 -   Ville M. Vainio ([@vivainio](https://github.com/vivainio))
 -   Virgil Dupras ([@hsoft](https://github.com/hsoft))
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -41,6 +41,7 @@ This document follows the conventions laid out in [Keep a CHANGELOG][].
 -   Fixed errors breaking .NET Remoting on method invoke ([#276][i276])
 -   Fixed PyObject.GetHashCode ([#676][i676])
 -   Fix memory leaks due to spurious handle incrementation ([#691][i691])
+-   Fix inheritance of non-abstract base methods ([#755][i755])
 
 
 ## [2.3.0][] - 2017-03-11
@@ -691,3 +692,4 @@ This document follows the conventions laid out in [Keep a CHANGELOG][].
 [p625]: https://github.com/pythonnet/pythonnet/pull/625
 [i131]: https://github.com/pythonnet/pythonnet/issues/131
 [p531]: https://github.com/pythonnet/pythonnet/pull/531
+[i755]: https://github.com/pythonnet/pythonnet/pull/755
diff --git a/src/runtime/methodbinder.cs b/src/runtime/methodbinder.cs
@@ -601,6 +601,19 @@ internal class MethodSorter : IComparer
     {
         int IComparer.Compare(object m1, object m2)
         {
+            var me1 = (MethodBase)m1;
+            var me2 = (MethodBase)m2;
+            if (me1.DeclaringType != me2.DeclaringType)
+            {
+                // m2's type derives from m1's type, favor m2
+                if (me1.DeclaringType.IsAssignableFrom(me2.DeclaringType))
+                    return 1;
+
+                // m1's type derives from m2's type, favor m1
+                if (me2.DeclaringType.IsAssignableFrom(me1.DeclaringType))
+                    return -1;
+            }
+
             int p1 = MethodBinder.GetPrecedence((MethodBase)m1);
             int p2 = MethodBinder.GetPrecedence((MethodBase)m2);
             if (p1 < p2)
diff --git a/src/testing/InheritanceTest.cs b/src/testing/InheritanceTest.cs
@@ -0,0 +1,14 @@
+using System;
+
+namespace Python.Test
+{
+    public class BaseClass
+    {
+        public bool IsBase() => true;
+    }
+
+    public class DerivedClass : BaseClass
+    {
+        public new bool IsBase() => false;
+    }
+}
diff --git a/src/testing/Python.Test.csproj b/src/testing/Python.Test.csproj
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+﻿<?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -83,6 +83,7 @@
     <Compile Include="generictest.cs" />
     <Compile Include="globaltest.cs" />
     <Compile Include="indexertest.cs" />
+    <Compile Include="InheritanceTest.cs" />
     <Compile Include="interfacetest.cs" />
     <Compile Include="methodtest.cs" />
     <Compile Include="moduletest.cs" />
@@ -110,4 +111,4 @@
     <Copy SourceFiles="$(TargetAssembly)" DestinationFolder="$(SolutionDir)\src\tests\fixtures" />
     <!--Copy SourceFiles="$(TargetAssemblyPdb)" Condition="Exists('$(TargetAssemblyPdb)')" DestinationFolder="$(PythonBuildDir)" /-->
   </Target>
-</Project>
+</Project>
diff --git a/src/tests/test_class.py b/src/tests/test_class.py
@@ -281,3 +281,14 @@ def PyCallback(self, self2):
     testobj.DoCallback()
     assert testobj.PyCallbackWasCalled
     assert testobj.SameReference
+
+
+def test_method_inheritance():
+    """Ensure that we call the overridden method instead of the one provided in
+       the base class."""
+
+    base = Test.BaseClass()
+    derived = Test.DerivedClass()
+
+    assert base.IsBase() == True
+    assert derived.IsBase() == False
