Fix marshalling of short integers

Author: BCSharp

src/core/IronPython.Modules/ModuleOps.cs

@@ -17,6 +17,7 @@
 using IronPython.Runtime.Exceptions;
 using IronPython.Runtime.Operations;
 using IronPython.Runtime.Types;
+using System.Runtime.CompilerServices;
 
 namespace IronPython.Modules {
     /// <summary>
@@ -526,12 +527,12 @@ public static int GetSignedInt(object value, object type) {
             throw PythonOps.TypeErrorForTypeMismatch("signed int", value);
         }
 
-        public static short GetUnsignedShort(object value, object type) {
+        public static ushort GetUnsignedShort(object value, object type) {
             int? res = Converter.ImplicitConvertToInt32(value);
             if (res != null) {
                 int iVal = res.Value;
                 if (iVal >= ushort.MinValue && iVal <= ushort.MaxValue) {
-                    return (short)(ushort)iVal;
+                    return (ushort)iVal;
                 }
             }
             if (PythonOps.TryGetBoundAttr(value, "_as_parameter_", out object asParam)) {
@@ -574,12 +575,12 @@ public static byte GetUnsignedByte(object value, object type) {
             throw PythonOps.TypeErrorForTypeMismatch("unsigned byte", value);
         }
 
-        public static byte GetSignedByte(object value, object type) {
+        public static sbyte GetSignedByte(object value, object type) {
             int? res = Converter.ImplicitConvertToInt32(value);
             if (res != null) {
                 int iVal = res.Value;
                 if (iVal >= sbyte.MinValue && iVal <= sbyte.MaxValue) {
-                    return (byte)(sbyte)iVal;
+                    return (sbyte)iVal;
                 }
             }
 

src/core/IronPython.Modules/_ctypes/SimpleType.cs

@@ -251,11 +251,11 @@ object INativeType.SetValue(MemoryHolder/*!*/ owner, int offset, object value) {
                 switch (_type) {
                     case SimpleTypeKind.Boolean: owner.WriteByte(offset, ModuleOps.GetBoolean(value, this)); break;
                     case SimpleTypeKind.Char: owner.WriteByte(offset, ModuleOps.GetChar(value, this)); break;
-                    case SimpleTypeKind.SignedByte: owner.WriteByte(offset, ModuleOps.GetSignedByte(value, this)); break;
+                    case SimpleTypeKind.SignedByte: owner.WriteByte(offset, (byte)ModuleOps.GetSignedByte(value, this)); break;
                     case SimpleTypeKind.UnsignedByte: owner.WriteByte(offset, ModuleOps.GetUnsignedByte(value, this)); break;
                     case SimpleTypeKind.WChar: owner.WriteInt16(offset, (short)ModuleOps.GetWChar(value, this)); break;
                     case SimpleTypeKind.SignedShort: owner.WriteInt16(offset, ModuleOps.GetSignedShort(value, this), _swap);  break;
-                    case SimpleTypeKind.UnsignedShort: owner.WriteInt16(offset, ModuleOps.GetUnsignedShort(value, this), _swap); break;
+                    case SimpleTypeKind.UnsignedShort: owner.WriteInt16(offset, (short)ModuleOps.GetUnsignedShort(value, this), _swap); break;
                     case SimpleTypeKind.VariantBool: owner.WriteInt16(offset, (short)ModuleOps.GetVariantBool(value, this), _swap); break;
                     case SimpleTypeKind.SignedInt: owner.WriteInt32(offset, ModuleOps.GetSignedInt(value, this), _swap); break;
                     case SimpleTypeKind.UnsignedInt: owner.WriteInt32(offset, ModuleOps.GetUnsignedInt(value, this), _swap); break;