From a4ce63abc598f93cca66d59fd196a7293b9566fb Mon Sep 17 00:00:00 2001
From: "Yukihiro \"Matz\" Matsumoto" <matz@ruby.or.jp>
Date: Wed, 20 Jul 2022 14:40:12 +0900
Subject: [PATCH] bigint.c (mpz_sizeinbase): check zero length bigint.

---
 mrbgems/mruby-bigint/core/bigint.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mrbgems/mruby-bigint/core/bigint.c b/mrbgems/mruby-bigint/core/bigint.c
index b8dc4487b..d984c2fdc 100644
--- a/mrbgems/mruby-bigint/core/bigint.c
+++ b/mrbgems/mruby-bigint/core/bigint.c
@@ -617,7 +617,10 @@ mpz_sizeinbase(mpz_t *x, int base)
 {
   int i,j;
   size_t bits = digits(x) * DIGITBITS;
+
   mrb_assert(2 <= base && base <= 36);
+
+  if (x->sz == 0) return 0;
   for (j=0,i=1; i<=base; i*=2,j++)
     ;
   return (int)((bits)/(j-1)+1);