allow Python not passing fake arguments for out parameters (#1672)

eirannejad · web-flow · commit f69753c701ea · 2022-01-13T18:55:42.000-08:00
diff --git a/AUTHORS.md b/AUTHORS.md
@@ -84,3 +84,4 @@
 -   ([@DanBarzilian](https://github.com/DanBarzilian))
 -   ([@alxnull](https://github.com/alxnull))
 -   ([@gpetrou](https://github.com/gpetrou))
+-   Ehsan Iran-Nejad ([@eirannejad](https://github.com/eirannejad))
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -109,6 +109,7 @@ Instead, `PyIterable` does that.
 -   Empty parameter names (as can be generated from F#) do not cause crashes
 -   Unicode strings with surrogates were truncated when converting from Python
 -   `Reload` mode now supports generic methods (previously Python would stop seeing them after reload)
+-   Temporarily fixed issue resolving method overload when method signature has `out` parameters ([#1672](i1672))
 
 ### Removed
 
@@ -881,3 +882,4 @@ This version improves performance on benchmarks significantly compared to 2.3.
 [i1342]: https://github.com/pythonnet/pythonnet/issues/1342
 [i238]: https://github.com/pythonnet/pythonnet/issues/238
 [i1481]: https://github.com/pythonnet/pythonnet/issues/1481
+[i1672]: https://github.com/pythonnet/pythonnet/pull/1672
diff --git a/src/runtime/MethodBinder.cs b/src/runtime/MethodBinder.cs
@@ -632,6 +632,11 @@ static BorrowedReference HandleParamsArray(BorrowedReference args, int arrayStar
                         margs[paramIndex] = defaultArgList[paramIndex - pyArgCount];
                     }
 
+                    if (parameter.ParameterType.IsByRef)
+                    {
+                        outs++;
+                    }
+
                     continue;
                 }
 
@@ -817,6 +822,9 @@ static bool MatchesArgumentCount(int positionalArgumentCount, ParameterInfo[] pa
                         defaultArgList.Add(parameters[v].GetDefaultValue());
                         defaultsNeeded++;
                     }
+                    else if (parameters[v].IsOut) {
+                        defaultArgList.Add(null);
+                    }
                     else if (!paramsArray)
                     {
                         match = false;
diff --git a/tests/test_method.py b/tests/test_method.py
@@ -280,6 +280,16 @@ def test_string_out_params():
     assert result[1] == "output string"
 
 
+def test_string_out_params_without_passing_string_value():
+    """Test use of string out-parameters."""
+    # @eirannejad 2022-01-13
+    result = MethodTest.TestStringOutParams("hi")
+    assert isinstance(result, tuple)
+    assert len(result) == 2
+    assert result[0] is True
+    assert result[1] == "output string"
+
+
 def test_string_ref_params():
     """Test use of string byref parameters."""
     result = MethodTest.TestStringRefParams("hi", "there")
@@ -308,6 +318,16 @@ def test_value_out_params():
         MethodTest.TestValueOutParams("hi", None)
 
 
+def test_value_out_params_without_passing_string_value():
+    """Test use of string out-parameters."""
+    # @eirannejad 2022-01-13
+    result = MethodTest.TestValueOutParams("hi")
+    assert isinstance(result, tuple)
+    assert len(result) == 2
+    assert result[0] is True
+    assert result[1] == 42
+
+
 def test_value_ref_params():
     """Test use of value type byref parameters."""
     result = MethodTest.TestValueRefParams("hi", 1)
@@ -336,6 +356,15 @@ def test_object_out_params():
     assert isinstance(result[1], System.Exception)
 
 
+def test_object_out_params_without_passing_string_value():
+    """Test use of object out-parameters."""
+    result = MethodTest.TestObjectOutParams("hi")
+    assert isinstance(result, tuple)
+    assert len(result) == 2
+    assert result[0] is True
+    assert isinstance(result[1], System.Exception)
+
+
 def test_object_ref_params():
     """Test use of object byref parameters."""
     result = MethodTest.TestObjectRefParams("hi", MethodTest())
@@ -364,6 +393,15 @@ def test_struct_out_params():
         MethodTest.TestValueRefParams("hi", None)
 
 
+def test_struct_out_params_without_passing_string_value():
+    """Test use of struct out-parameters."""
+    result = MethodTest.TestStructOutParams("hi")
+    assert isinstance(result, tuple)
+    assert len(result) == 2
+    assert result[0] is True
+    assert isinstance(result[1], System.Guid)
+
+
 def test_struct_ref_params():
     """Test use of struct byref parameters."""
     result = MethodTest.TestStructRefParams("hi", System.Guid.NewGuid())

Original file line number	Diff line number	Diff line change
`@@ -632,6 +632,11 @@ static BorrowedReference HandleParamsArray(BorrowedReference args, int arrayStar`
`632`	`632`	`margs[paramIndex] = defaultArgList[paramIndex - pyArgCount];`
`633`	`633`	`}`
`634`	`634`
	`635`	`+ if (parameter.ParameterType.IsByRef)`
	`636`	`+ {`
	`637`	`+ outs++;`
	`638`	`+ }`
	`639`	`+`
`635`	`640`	`continue;`
`636`	`641`	`}`
`637`	`642`
`@@ -817,6 +822,9 @@ static bool MatchesArgumentCount(int positionalArgumentCount, ParameterInfo[] pa`
`817`	`822`	`defaultArgList.Add(parameters[v].GetDefaultValue());`
`818`	`823`	`defaultsNeeded++;`
`819`	`824`	`}`
	`825`	`+ else if (parameters[v].IsOut) {`
	`826`	`+ defaultArgList.Add(null);`
	`827`	`+ }`
`820`	`828`	`else if (!paramsArray)`
`821`	`829`	`{`
`822`	`830`	`match = false;`