From b3be4710aaa53429c78d03a86e9be909dca923c0 Mon Sep 17 00:00:00 2001
From: Paul Sokolovsky <pfalcon@users.sourceforge.net>
Date: Sun, 22 Nov 2015 22:03:18 +0200
Subject: [PATCH] py/mpz: Normalize (remove leading zeros) xor operation
 result.

---
 py/mpz.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/py/mpz.c b/py/mpz.c
index e0475d60a1..2a4fb4659d 100644
--- a/py/mpz.c
+++ b/py/mpz.c
@@ -285,7 +285,11 @@ STATIC mp_uint_t mpn_xor(mpz_dig_t *idig, const mpz_dig_t *jdig, mp_uint_t jlen,
         *idig = *jdig;
     }
 
-    return idig - oidig;
+    // remove trailing zeros
+    for (--idig; idig >= oidig && *idig == 0; --idig) {
+    }
+
+    return idig + 1 - oidig;
 }
 
 /* computes i = i * d1 + d2