1 files changed, 5 insertions, 1 deletions
diff --git a/bignum.c b/bignum.c
index 537852d959..4db4bdb6a6 100644
--- a/bignum.c
+++ b/bignum.c
@@ -1243,7 +1243,8 @@ bigdivmod(x, y, divp, modp)
     VALUE mod;
 
     bigdivrem(x, y, divp, &mod);
-    if (RBIGNUM(x)->sign != RBIGNUM(y)->sign && RBIGNUM(mod)->len > 0) {
+    if (RBIGNUM(x)->sign != RBIGNUM(y)->sign &&
+	RBIGNUM(mod)->len > 0 && BDIGITS(mod)[0] != 0) {
 	if (divp) *divp = bigadd(*divp, rb_int2big(1), 0);
 	if (modp) *modp = bigadd(mod, y, 1);
     }
@@ -1603,6 +1604,9 @@ rb_big_rshift(x, y)
     xds = BDIGITS(x);
     i = RBIGNUM(x)->len; j = i - s1;
     z = bignew(j, RBIGNUM(x)->sign);
+    if (!RBIGNUM(x)->sign) {
+	num = ((BDIGIT_DBL)~0) << BITSPERDIG;
+    }
     zds = BDIGITS(z);
     while (i--, j--) {
 	num = (num | xds[i]) >> s2;