merges r23361 from trunk into ruby_1_9_1.

--
* array.c (rb_ary_flatten_bang): returns nil if nothing changed.
  a patch from Marc-Andre Lafortune in [ruby-core:23382].

git-svn-id: http://svn.ruby-lang.org/repos/ruby/branches/ruby_1_9_1@23513 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 1 deletions

diff --git a/array.c b/array.c
index 330162160..6923b382c 100644
--- a/array.c
+++ b/array.c
@@ -3190,7 +3190,7 @@ rb_ary_flatten_bang(int argc, VALUE *argv, VALUE ary)
 
     rb_scan_args(argc, argv, "01", &lv);
     if (!NIL_P(lv)) level = NUM2INT(lv);
-    if (level == 0) return ary;
+    if (level == 0) return Qnil;
 
     result = flatten(ary, level, &mod);
     if (mod == 0) return Qnil;