merges r20840 from trunk into ruby_1_9_1.

* array.c (rb_ary_push_m): add modification check before actual
  operation.   [ruby-dev:37440]

git-svn-id: http://svn.ruby-lang.org/repos/ruby/branches/ruby_1_9_1@20873 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 0 deletions

diff --git a/array.c b/array.c
index 535cfd060..3ba450cbe 100644
--- a/array.c
+++ b/array.c
@@ -693,6 +693,7 @@ rb_ary_push(VALUE ary, VALUE item)
 static VALUE
 rb_ary_push_m(int argc, VALUE *argv, VALUE ary)
 {
+    rb_ary_modify_check(ary);
     while (argc--) {
 	rb_ary_push(ary, *argv++);
     }