pythonnet · filmor · Oct 1, 2020 · Sep 30, 2020
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -22,6 +22,7 @@ details about the cause of the failure
 -    Fix incorrect dereference in params array handling
 -    Fix `object[]` parameters taking precedence when should not in overload resolution
 -    Fixed a bug where all .NET class instances were considered Iterable
+-    Fix incorrect choice of method to invoke when using keyword arguments.

 ## [2.5.0][] - 2020-06-14


diff --git a/src/runtime/constructorbinder.cs b/src/runtime/constructorbinder.cs
@@ -89,7 +89,7 @@ internal object InvokeRaw(IntPtr inst, IntPtr args, IntPtr kw, MethodBase info)
                // any extra args are intended for the subclass' __init__.

                IntPtr eargs = Runtime.PyTuple_New(0);
-                binding = Bind(inst, eargs, kw);
+                binding = Bind(inst, eargs, IntPtr.Zero);
                Runtime.XDecref(eargs);

                if (binding == null)

diff --git a/src/runtime/methodbinder.cs b/src/runtime/methodbinder.cs
@@ -580,7 +580,7 @@ static bool MatchesArgumentCount(int positionalArgumentCount, ParameterInfo[] pa
            var match = false;
            paramsArray = parameters.Length > 0 ? Attribute.IsDefined(parameters[parameters.Length - 1], typeof(ParamArrayAttribute)) : false;

-            if (positionalArgumentCount == parameters.Length)
+            if (positionalArgumentCount == parameters.Length && kwargDict.Count == 0)
            {
                match = true;
            }

diff --git a/src/testing/methodtest.cs b/src/testing/methodtest.cs
@@ -699,6 +699,12 @@ public string PublicMethod(string echo)
            return echo;
        }
    }
+
+    public class MethodArityTest
+    {
+        public string Foo(int a) { return "Arity 1"; }
+        public string Foo(int a, int b) { return "Arity 2"; }
+    }
 }

 namespace PlainOldNamespace

diff --git a/src/tests/test_method.py b/src/tests/test_method.py
@@ -1149,3 +1149,10 @@ def test_optional_and_default_params():

    res = MethodTest.OptionalAndDefaultParams2(b=2, c=3)
    assert res == "0232"
+
+def test_keyword_arg_method_resolution():
+    from Python.Test import MethodArityTest
+
+    ob = MethodArityTest()
+    assert ob.Foo(1, b=2) == "Arity 2"
+