fix for #95, fix for #94

neo/BigInteger.py

@@ -5,6 +5,14 @@
 
 class BigInteger(int):
 
+    @property
+    def Sign(self):
+        if self > 0:
+            return 1
+        elif self == 0:
+            return 0
+        return -1
+
     @staticmethod
     def FromBytes(data, signed=False):
         return BigInteger(int.from_bytes(data, 'little', signed=signed))

neo/VM/InteropService.py

@@ -258,9 +258,10 @@ def __init__(self, value):
         super(Struct, self).__init__(value)
 
     def Clone(self):
-        newArray = []
+        length = len(self._array)
+        newArray = [None for i in range(0, length)]
 
-        for i in range(0, len(self._array)):
+        for i in range(0, length):
             if self._array[i] is None:
                 newArray[i] = None
             elif self._array[i].IsStruct:

neo/test_numbers.py

@@ -153,6 +153,24 @@ def test_big_integer_frombytes(self):
         self.assertEqual(b1, b2)
         self.assertTrue(b1.Equals(b2))
 
+    def test_big_integer_sign(self):
+
+        b1 = BigInteger(3)
+        b2 = BigInteger(0)
+        b3 = BigInteger(-4)
+        self.assertEqual(b1.Sign, 1)
+        self.assertEqual(b2.Sign, 0)
+        self.assertEqual(b3.Sign, -1)
+
+        c1 = BigInteger(-100)
+        c1_bytes = c1.ToByteArray()
+
+        c2 = BigInteger.FromBytes(c1_bytes, signed=True)
+        self.assertEqual(c2.Sign, -1)
+
+        c2_unsigned = BigInteger.FromBytes(c1_bytes, signed=False)
+        self.assertEqual(c2_unsigned.Sign, 1)
+
 
 class UIntBaseTestCase(NeoTestCase):
     def test_initialization(self):