# HG changeset patch
# User Franz Glasner <fzglas.hg@dom66.de>
# Date 1737564949 -3600
# Node ID 73d22943da5acb56e06cd2237a0ac4ad3104f18b
# Parent  63088d3675bbefc60a7449335751b10e4ed4b826
FIX: CRC-32 validation on Python2.7: normalize to positive numbers

diff -r 63088d3675bb -r 73d22943da5a cutils/treesum.py
--- a/cutils/treesum.py	Wed Jan 22 17:45:37 2025 +0100
+++ b/cutils/treesum.py	Wed Jan 22 17:55:49 2025 +0100
@@ -999,7 +999,22 @@
         self._crc32 = zlib.crc32(data, self._crc32)
 
     def _hex_crc(self):
-        return (hex(self._crc32)[2:]).upper()
+        return (hex(self._get_crc())[2:]).upper()
+
+    def _get_crc(self):
+        """Get the current CRC always as positive number with the same bit#
+        pattern because Python2 yields negative numbers also.
+
+        :return: The current CRC value as positive  number on all Python
+                 versions
+        :rtype: int
+
+        """
+        if util.PY2:
+            # Return the bitpattern as unsigned 32-bit number
+            return (~self._crc32 ^ 0xFFFFFFFF)
+        else:
+            return self._crc32
 
     def _get_digest_size(self, algo_name):
         if self._current_algo_name == algo_name: