numeric.c (rb_int_digits): Fix exception message

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56554 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Fri Nov  4 13:03:00 2016  Kenta Murata  <mrkn@mrkn.jp>
+
+	* numeric.c (rb_int_digits): Fix exception message
+
 Fri Nov  4 10:51:16 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/pathname/pathname.c (path_hash): fix unnormalized Fixnum

numeric.c

@@ -4680,7 +4680,9 @@ rb_int_digits(int argc, VALUE *argv, VALUE num)
             return rb_int_digits_bigbase(num, base_value);
 
         base = FIX2LONG(base_value);
-        if (base < 2)
+        if (base < 0)
+            rb_raise(rb_eArgError, "negative radix");
+        else if (base < 2)
             rb_raise(rb_eArgError, "invalid radix %ld", base);
     }
     else