More tests, and fixed none negative bigint xor

1 files changed, 4 insertions, 2 deletions

diff --git a/src/bigint.cpp b/src/bigint.cpp
index 05c6463aa3..85e5dad4ad 100644
--- a/src/bigint.cpp
+++ b/src/bigint.cpp
@@ -1295,14 +1295,16 @@ void bigint_xor(BigInt *dest, const BigInt *op1, const BigInt *op2) {
         dest->is_negative = false;
         const uint64_t *op1_digits = bigint_ptr(op1);
         const uint64_t *op2_digits = bigint_ptr(op2);
+
+        assert(op1->digit_count > 0 && op2->digit_count > 0);
+        uint64_t first_digit = op1_digits[0] ^ op2_digits[0];
         if (op1->digit_count == 1 && op2->digit_count == 1) {
             dest->digit_count = 1;
-            dest->data.digit = op1_digits[0] ^ op2_digits[0];
+            dest->data.digit = first_digit;
             bigint_normalize(dest);
             return;
         }
         // TODO this code path is untested
-        uint64_t first_digit = dest->data.digit;
         dest->digit_count = max(op1->digit_count, op2->digit_count);
         dest->data.digits = allocate_nonzero<uint64_t>(dest->digit_count);
         dest->data.digits[0] = first_digit;