* bignum.c (rb_ll2big): Don't overflow on signed integer negation.

* ext/bigdecimal/bigdecimal.c (MUL_OVERFLOW_SIGNED_VALUE_P): New
  macro.
  (AddExponent): Don't overflow on signed integer multiplication.
  (VpCtoV): Don't overflow on signed integer arithmetic.
  (VpCtoV): Don't overflow on signed integer arithmetic.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40214 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 6 insertions, 2 deletions

diff --git a/bignum.c b/bignum.c
index 7d4bd3cb17..e709c21c52 100644
--- a/bignum.c
+++ b/bignum.c
@@ -832,13 +832,17 @@ static VALUE
 rb_ll2big(LONG_LONG n)
 {
     long neg = 0;
+    unsigned LONG_LONG u;
     VALUE big;
 
     if (n < 0) {
-	n = -n;
+        u = 1 + (unsigned LONG_LONG)(-(n + 1)); /* u = -n avoiding overflow */
 	neg = 1;
     }
-    big = rb_ull2big(n);
+    else {
+        u = n;
+    }
+    big = rb_ull2big(u);
     if (neg) {
 	RBIGNUM_SET_SIGN(big, 0);
     }