[GR-47378] Compare bytes as unsigned bytes

PullRequest: graalpython/2870

Author: ppisl

graalpython/com.oracle.graal.python.test/src/tests/test_bytes.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2018, 2022, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # The Universal Permissive License (UPL), Version 1.0
@@ -184,6 +184,9 @@ def test_setitem():
     except TypeError:
         pass
 
+def test_unsignedByte():
+    assert b'\x80' > b'\x00'
+    assert not b'\x80' < b'\x00'
 
 class BaseGetSlice:
     def assertEqualWithType(self, a, b):

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/bytes/BytesNodes.java

@@ -966,7 +966,7 @@ protected boolean doCmp(byte[] selfArray, int selfLength, byte[] otherArray, int
                 return shortcutLengthResult();
             }
             for (int i = 0; i < Math.min(selfLength, otherLength); i++) {
-                compareResult = Byte.compare(selfArray[i], otherArray[i]);
+                compareResult = Byte.compareUnsigned(selfArray[i], otherArray[i]);
                 if (compareResult != 0) {
                     break;
                 }