merges r27848 from trunk into ruby_1_9_2.

--
* eval.c (setup_exception): let SystemStackError#backtrace return an
  single element array instead of string itself.  [ruby-core:30196]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@27969 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 0 deletions

diff --git a/eval.c b/eval.c
index 99f28dc8e6..95d1b8c860 100644
--- a/eval.c
+++ b/eval.c
@@ -380,6 +380,7 @@ setup_exception(rb_thread_t *th, int tag, volatile VALUE mesg)
     if (file && !NIL_P(mesg)) {
 	if (mesg == sysstack_error) {
 	    at = rb_enc_sprintf(rb_usascii_encoding(), "%s:%d", file, line);
+	    at = rb_ary_new3(1, at);
 	    rb_iv_set(mesg, "bt", at);
 	}
 	else {