Misc changes (#973)

* Make from_bytes a class method

* Fix empty deque comparison

* Fix hex(BigInteger)

* Update after review

Author: slozier

Src/IronPython.Modules/_collections.cs

@@ -486,16 +486,13 @@ int IComparable.CompareTo(object obj) {
                 return CompareToWorker(otherDeque);
             }
 
-            private int CompareToWorker(deque otherDeque) {
-                return CompareToWorker(otherDeque, null);
-            }
-
-            private int CompareToWorker(deque otherDeque, IComparer comparer) {
+            private int CompareToWorker(deque otherDeque, IComparer comparer = null) {
                 Assert.NotNull(otherDeque);
 
-                if (otherDeque._itemCnt == 0 && _itemCnt == 0) {
-                    // comparing two empty deques
-                    return 0;
+                if (_itemCnt == 0) {
+                    return otherDeque._itemCnt == 0 ? 0 : -1;
+                } else if (otherDeque._itemCnt == 0) {
+                    return 1;
                 }
 
                 if (CompareUtil.Check(this)) return 0;

Src/IronPython/Modules/Builtin.cs

@@ -625,10 +625,12 @@ private static void AppendIndent(StringBuilder doc, int indent) {
         public static string hex(object? o) {
             object res = PythonOps.Index(o);
             if (res is BigInteger b) {
-                if (b < 0) {
-                    return "-0x" + (-b).ToString("x");
+                if (b == 0) {
+                    return "0x0";
+                } else if (b < 0) {
+                    return "-0x" + ToHexString(-b);
                 } else {
-                    return "0x" + b.ToString("x");
+                    return "0x" + ToHexString(b);
                 }
             }
 
@@ -638,6 +640,12 @@ public static string hex(object? o) {
             } else {
                 return "0x" + Convert.ToString(x, 16);
             }
+
+            static string ToHexString(BigInteger b) {
+                var val = b.ToString("x");
+                if (val[0] == '0') val = val.TrimStart('0'); // BigInteger.ToString("x") sometimes pads with 0 so we need to trim it (https://github.com/dotnet/runtime/issues/43269)
+                return val;
+            }
         }
 
         public static object id(object? o) {

Src/IronPython/Runtime/ClassMethodDescriptor.cs

@@ -18,7 +18,7 @@ internal ClassMethodDescriptor(BuiltinFunction func) {
 
         internal override bool TryGetValue(CodeContext context, object instance, PythonType owner, out object value) {
             owner = CheckGetArgs(context, instance, owner);
-            value = new Method(_func, owner);
+            value = new BuiltinFunction(owner, _func._data);
             return true;
         }
 

Src/IronPython/Runtime/Operations/IntOps.cs

@@ -528,10 +528,9 @@ public static Bytes to_bytes(Int32 value, int length, string byteorder, bool sig
             return Bytes.Make(res.ToArray());
         }
 
-        public static BigInteger from_bytes(CodeContext context, object bytes, [NotNull] string byteorder, bool signed = false) {
+        [ClassMethod, StaticExtensionMethod]
+        public static object from_bytes(CodeContext context, PythonType type, object bytes, [NotNull] string byteorder, bool signed = false) {
             // TODO: signed should be a keyword only argument
-            // TODO: return int when possible?
-            // TODO: if called on a subclass of Extensible<BigInteger>, return that subclass
 
             bool isLittle = byteorder == "little";
             if (!isLittle && byteorder != "big") throw PythonOps.ValueError("byteorder must be either 'little' or 'big'");
@@ -540,19 +539,13 @@ public static BigInteger from_bytes(CodeContext context, object bytes, [NotNull]
             if (bytesArr.Length == 0) return 0;
 
 #if NETCOREAPP
-            return new BigInteger(bytesArr.AsSpan(), isUnsigned: !signed, isBigEndian: !isLittle);
+            var val = new BigInteger(bytesArr.AsSpan(), isUnsigned: !signed, isBigEndian: !isLittle);
 #else
-
-            if (isLittle) {
-                bool msbSet = (bytesArr[bytesArr.Length - 1] & 0x80) == 0x80;
-                if (!msbSet) return new BigInteger(bytesArr);
-                return new BigInteger(bytesArr.Concat(Enumerable.Repeat<byte>(signed ? (byte)0xff : (byte)0, 1)).ToArray());
-            } else {
-                bool msbSet = (bytesArr[0] & 0x80) == 0x80;
-                if (!msbSet) return new BigInteger(bytesArr.Reverse());
-                return new BigInteger(bytesArr.Reverse().Concat(Enumerable.Repeat<byte>(signed ? (byte)0xff : (byte)0, 1)).ToArray());
-            }
+            if (!isLittle) bytesArr = bytesArr.Reverse();
+            if (!signed && (bytesArr[bytesArr.Length - 1] & 0x80) == 0x80) Array.Resize(ref bytesArr, bytesArr.Length + 1);
+            var val = new BigInteger(bytesArr);
 #endif
+            return __new__(context, type, val);
         }
 
         public static int __round__(int self) {

Tests/test_builtinfunc.py

@@ -1068,6 +1068,10 @@ def __index__(self):
             self.assertEqual([(2147483647, 2), (2147483648, 3), (2147483649, 4)], list(enumerate([2,3,4], value_maker(int((1<<31) - 1)))))
             self.assertEqual([(2147483648, 2), (2147483649, 3), (2147483650, 4)], list(enumerate([2,3,4], value_maker(1<<31))))
 
+    def test_hex_long(self):
+        """https://github.com/IronLanguages/ironpython3/pull/973"""
+        self.assertEqual(hex(0x800000000), '0x800000000')
+
 # temp_func = in_main()
 # locals_globals = 7
 # temp_func()

Tests/test_deque.py

@@ -0,0 +1,18 @@
+# Licensed to the .NET Foundation under one or more agreements.
+# The .NET Foundation licenses this file to you under the Apache 2.0 License.
+# See the LICENSE file in the project root for more information.
+
+from _collections import deque
+import unittest
+
+class DequeTest(unittest.TestCase):
+    def test_deque_cmp_empty(self):
+        """https://github.com/IronLanguages/ironpython3/pull/973"""
+        class AlwaysLessThan:
+            def __lt__(self, other):
+                return True
+
+        self.assertFalse(deque([AlwaysLessThan()]) < deque())
+
+if __name__ == "__main__":
+    unittest.main()

Tests/test_int.py

@@ -0,0 +1,15 @@
+# Licensed to the .NET Foundation under one or more agreements.
+# The .NET Foundation licenses this file to you under the Apache 2.0 License.
+# See the LICENSE file in the project root for more information.
+
+import unittest
+
+class IntSubclass(int): pass
+
+class IntTest(unittest.TestCase):
+    def test_from_bytes(self):
+        self.assertEqual(type(int.from_bytes(b"abc", "big")), int)
+        self.assertEqual(type(IntSubclass.from_bytes(b"abc", "big")), IntSubclass) # https://github.com/IronLanguages/ironpython3/pull/973
+
+if __name__ == "__main__":
+    unittest.main()