rb_ary_aplice, rb_ary_times): integer overflows should be
  checked. based on patches from Drew Yao <ayao at apple.com>
  fixed CVE-2008-2726

* string.c (rb_str_buf_append): fixed unsafe use of alloca,
  which led memory corruption. based on a patch from Drew Yao
  <ayao at apple.com> fixed CVE-2008-2726

* sprintf.c (rb_str_format): backported from trunk.

* intern.h: ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8_7@17460 b2dd03c8-39d4-4d8f-98ff-823fe69b080e