1 files changed, 13 insertions, 4 deletions
diff --git a/error.c b/error.c
index 90f04829f9..1be043057a 100644
--- a/error.c
+++ b/error.c
@@ -673,9 +673,17 @@ static VALUE
 exc_backtrace(VALUE exc)
 {
     ID bt;
+    VALUE obj;
 
     CONST_ID(bt, "bt");
-    return rb_attr_get(exc, bt);
+    obj = rb_attr_get(exc, bt);
+
+    if (rb_backtrace_p(obj)) {
+	obj = rb_backtrace_to_str_ary(obj);
+	/* rb_iv_set(exc, "bt", obj); */
+    }
+
+    return obj;
 }
 
 VALUE
@@ -686,6 +694,7 @@ rb_check_backtrace(VALUE bt)
 
     if (!NIL_P(bt)) {
 	if (RB_TYPE_P(bt, T_STRING)) return rb_ary_new3(1, bt);
+	if (rb_backtrace_p(bt)) return bt;
 	if (!RB_TYPE_P(bt, T_ARRAY)) {
 	    rb_raise(rb_eTypeError, err);
 	}
@@ -708,8 +717,8 @@ rb_check_backtrace(VALUE bt)
  *
  */
 
-static VALUE
-exc_set_backtrace(VALUE exc, VALUE bt)
+VALUE
+rb_exc_set_backtrace(VALUE exc, VALUE bt)
 {
     return rb_iv_set(exc, "bt", rb_check_backtrace(bt));
 }
@@ -1669,7 +1678,7 @@ Init_Exception(void)
     rb_define_method(rb_eException, "message", exc_message, 0);
     rb_define_method(rb_eException, "inspect", exc_inspect, 0);
     rb_define_method(rb_eException, "backtrace", exc_backtrace, 0);
-    rb_define_method(rb_eException, "set_backtrace", exc_set_backtrace, 1);
+    rb_define_method(rb_eException, "set_backtrace", rb_exc_set_backtrace, 1);
 
     rb_eSystemExit  = rb_define_class("SystemExit", rb_eException);
     rb_define_method(rb_eSystemExit, "initialize", exit_initialize, -1);