merges r23359 from trunk into ruby_1_9_1.

--
* array.c (rb_ary_sample): negative sample number is invalid.
  [ruby-core:23374]

git-svn-id: http://svn.ruby-lang.org/repos/ruby/branches/ruby_1_9_1@23512 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 2 deletions

diff --git a/array.c b/array.c
index bc342b586..330162160 100644
--- a/array.c
+++ b/array.c
@@ -3302,8 +3302,9 @@ rb_ary_sample(int argc, VALUE *argv, VALUE ary)
     }
     rb_scan_args(argc, argv, "1", &nv);
     n = NUM2LONG(nv);
-    ptr = RARRAY_PTR(ary); 
-    len = RARRAY_LEN(ary); 
+    if (n < 0) rb_raise(rb_eArgError, "negative sample number");
+    ptr = RARRAY_PTR(ary);
+    len = RARRAY_LEN(ary);
     if (n > len) n = len;
     switch (n) {
       case 0: return rb_ary_new2(0);