error.c: redefined backtrace

* error.c (rb_get_backtrace): honor redefined Exception#backtrace
  method.  [ruby-core:78097] [Bug #12925]

* eval.c (setup_exception): rescue exceptions during backtrace
  setup.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56767 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 19 insertions, 6 deletions

diff --git a/eval.c b/eval.c
index 865dc8c8e0..6b4acf575d 100644
--- a/eval.c
+++ b/eval.c
@@ -507,13 +507,25 @@ setup_exception(rb_thread_t *th, int tag, volatile VALUE mesg, VALUE cause)
 		rb_ivar_set(mesg, idBt_locations, at);
 	    }
 	}
-	else if (NIL_P(rb_get_backtrace(mesg))) {
-	    at = rb_vm_backtrace_object();
-	    if (OBJ_FROZEN(mesg)) {
-		mesg = rb_obj_dup(mesg);
+	else {
+	    int status;
+
+	    TH_PUSH_TAG(th);
+	    if ((status = EXEC_TAG()) == 0) {
+		VALUE bt;
+		if (rb_threadptr_set_raised(th)) goto fatal;
+		bt = rb_get_backtrace(mesg);
+		if (NIL_P(bt)) {
+		    at = rb_vm_backtrace_object();
+		    if (OBJ_FROZEN(mesg)) {
+			mesg = rb_obj_dup(mesg);
+		    }
+		    rb_ivar_set(mesg, idBt_locations, at);
+		    set_backtrace(mesg, at);
+		}
+		rb_threadptr_reset_raised(th);
 	    }
-	    rb_ivar_set(mesg, idBt_locations, at);
-	    set_backtrace(mesg, at);
+	    TH_POP_TAG();
 	}
     }
 
@@ -556,6 +568,7 @@ setup_exception(rb_thread_t *th, int tag, volatile VALUE mesg, VALUE cause)
     }
 
     if (rb_threadptr_set_raised(th)) {
+      fatal:
 	th->errinfo = exception_error;
 	rb_threadptr_reset_raised(th);
 	TH_JUMP_TAG(th, TAG_FATAL);