merge revision(s) 56111: [Backport #12738]

	* array.c (flatten): use rb_obj_class instead of rb_class_of
	  because rb_class_of may return a singleton class.
	  [ruby-dev:49781] [Bug #12738]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@56233 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 1 deletions

diff --git a/array.c b/array.c
index dd14837b76..729de9c081 100644
--- a/array.c
+++ b/array.c
@@ -4461,7 +4461,7 @@ flatten(VALUE ary, int level, int *modified)
 
     st_free_table(memo);
 
-    RBASIC_SET_CLASS(result, rb_class_of(ary));
+    RBASIC_SET_CLASS(result, rb_obj_class(ary));
     return result;
 }