fix object[] parameters taking precedence when should not in overload resolution

lostmsu · lostmsu · commit eaed5c25104a · 2020-09-14T21:42:15.000-07:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -19,6 +19,7 @@ details about the cause of the failure
 
 -    Fix incorrect dereference of wrapper object in `tp_repr`, which may result in a program crash
 -    Fix incorrect dereference in params array handling
+-    Fix `object[]` parameters taking precedence when should not in overload resolution
 
 ## [2.5.0][] - 2020-06-14
 
diff --git a/src/runtime/methodbinder.cs b/src/runtime/methodbinder.cs
@@ -203,6 +203,16 @@ internal static int ArgPrecedence(Type t)
                 return 3000;
             }
 
+            if (t.IsArray)
+            {
+                Type e = t.GetElementType();
+                if (e == objectType)
+                {
+                    return 2500;
+                }
+                return 100 + ArgPrecedence(e);
+            }
+
             TypeCode tc = Type.GetTypeCode(t);
             // TODO: Clean up
             switch (tc)
@@ -250,16 +260,6 @@ internal static int ArgPrecedence(Type t)
                     return 40;
             }
 
-            if (t.IsArray)
-            {
-                Type e = t.GetElementType();
-                if (e == objectType)
-                {
-                    return 2500;
-                }
-                return 100 + ArgPrecedence(e);
-            }
-
             return 2000;
         }
 
diff --git a/src/testing/methodtest.cs b/src/testing/methodtest.cs
@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using System.Linq;
 using System.Runtime.InteropServices;
 
 namespace Python.Test
@@ -84,7 +85,7 @@ public Type[] TestNullArrayConversion(Type[] v)
 
         public static string[] TestStringParamsArg(params string[] args)
         {
-            return args;
+            return args.Concat(new []{"tail"}).ToArray();
         }
 
         public static object[] TestObjectParamsArg(params object[] args)
diff --git a/src/tests/test_method.py b/src/tests/test_method.py
@@ -206,17 +206,20 @@ def test_null_array_conversion():
 def test_string_params_args():
     """Test use of string params."""
     result = MethodTest.TestStringParamsArg('one', 'two', 'three')
-    assert result.Length == 3
-    assert len(result) == 3, result
+    assert result.Length == 4
+    assert len(result) == 4, result
     assert result[0] == 'one'
     assert result[1] == 'two'
     assert result[2] == 'three'
+    # ensures params string[] overload takes precedence over params object[]
+    assert result[3] == 'tail'
 
     result = MethodTest.TestStringParamsArg(['one', 'two', 'three'])
-    assert len(result) == 3
+    assert len(result) == 4
     assert result[0] == 'one'
     assert result[1] == 'two'
     assert result[2] == 'three'
+    assert result[3] == 'tail'
 
 
 def test_object_params_args():

Original file line number	Diff line number	Diff line change
`@@ -1,5 +1,6 @@`
`1`	`1`	`using System;`
`2`	`2`	`using System.IO;`
	`3`	`+using System.Linq;`
`3`	`4`	`using System.Runtime.InteropServices;`
`4`	`5`
`5`	`6`	`namespace Python.Test`
`@@ -84,7 +85,7 @@ public Type[] TestNullArrayConversion(Type[] v)`
`84`	`85`
`85`	`86`	`public static string[] TestStringParamsArg(params string[] args)`
`86`	`87`	`{`
`87`		`- return args;`
	`88`	`+ return args.Concat(new []{"tail"}).ToArray();`
`88`	`89`	`}`
`89`	`90`
`90`	`91`	`public static object[] TestObjectParamsArg(params object[] args)`