From d432839cbdefc792adce02f9ea759bb2bb3249fd Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Sun, 13 Nov 2016 05:25:53 +0000
Subject: [PATCH] error.c: rb_get_backtrace

* error.c (rb_get_backtrace): move from eval_error.c to call
  exc_backtrace directly.  [ruby-core:78097] [Bug #12925]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56766 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 error.c                     | 16 ++++++++++++++++
 eval.c                      |  4 ++--
 eval_error.c                | 21 ++-------------------
 test/ruby/test_exception.rb | 13 +++++++++++++
 4 files changed, 33 insertions(+), 21 deletions(-)

diff --git a/error.c b/error.c
index 0856bc0e2a..4503742896 100644
--- a/error.c
+++ b/error.c
@@ -882,6 +882,22 @@ exc_backtrace(VALUE exc)
     return obj;
 }
 
+VALUE
+rb_get_backtrace(VALUE exc)
+{
+    VALUE info, klass = rb_eException;
+    ID mid = id_backtrace;
+    rb_thread_t *th = GET_THREAD();
+    if (NIL_P(exc))
+	return Qnil;
+    EXEC_EVENT_HOOK(th, RUBY_EVENT_C_CALL, exc, mid, mid, klass, Qundef);
+    info = exc_backtrace(exc);
+    EXEC_EVENT_HOOK(th, RUBY_EVENT_C_RETURN, exc, mid, mid, klass, info);
+    if (NIL_P(info))
+	return Qnil;
+    return rb_check_backtrace(info);
+}
+
 /*
  *  call-seq:
  *     exception.backtrace_locations    -> array
diff --git a/eval.c b/eval.c
index dcba1e16d0..865dc8c8e0 100644
--- a/eval.c
+++ b/eval.c
@@ -507,7 +507,7 @@ setup_exception(rb_thread_t *th, int tag, volatile VALUE mesg, VALUE cause)
 		rb_ivar_set(mesg, idBt_locations, at);
 	    }
 	}
-	else if (NIL_P(get_backtrace(mesg))) {
+	else if (NIL_P(rb_get_backtrace(mesg))) {
 	    at = rb_vm_backtrace_object();
 	    if (OBJ_FROZEN(mesg)) {
 		mesg = rb_obj_dup(mesg);
@@ -1616,7 +1616,7 @@ errat_getter(ID id)
 {
     VALUE err = get_errinfo();
     if (!NIL_P(err)) {
-	return get_backtrace(err);
+	return rb_get_backtrace(err);
     }
     else {
 	return Qnil;
diff --git a/eval_error.c b/eval_error.c
index cfb82d3a24..c469474159 100644
--- a/eval_error.c
+++ b/eval_error.c
@@ -49,23 +49,6 @@ error_pos_str(void)
     return Qnil;
 }
 
-static VALUE
-get_backtrace(VALUE info)
-{
-    if (NIL_P(info))
-	return Qnil;
-    info = rb_funcall(info, rb_intern("backtrace"), 0);
-    if (NIL_P(info))
-	return Qnil;
-    return rb_check_backtrace(info);
-}
-
-VALUE
-rb_get_backtrace(VALUE info)
-{
-    return get_backtrace(info);
-}
-
 static void
 set_backtrace(VALUE info, VALUE bt)
 {
@@ -80,7 +63,7 @@ set_backtrace(VALUE info, VALUE bt)
 	    bt = rb_backtrace_to_str_ary(bt);
 	}
     }
-    rb_funcall(info, rb_intern("set_backtrace"), 1, bt);
+    rb_check_funcall(info, set_backtrace, 1, &bt);
 }
 
 static void
@@ -105,7 +88,7 @@ rb_threadptr_error_print(rb_thread_t *th, VALUE errinfo)
 
     TH_PUSH_TAG(th);
     if (TH_EXEC_TAG() == 0) {
-	errat = get_backtrace(errinfo);
+	errat = rb_get_backtrace(errinfo);
     }
     else if (errat == Qundef) {
 	errat = Qnil;
diff --git a/test/ruby/test_exception.rb b/test/ruby/test_exception.rb
index 91d3ac1e93..32918df16d 100644
--- a/test/ruby/test_exception.rb
+++ b/test/ruby/test_exception.rb
@@ -952,4 +952,17 @@ $stderr = $stdout; raise "\x82\xa0"') do |outs, errs, status|
       ::Warning.warn "\x00a\x00b\x00c".force_encoding("utf-16be")
     end
   end
+
+  def test_undefined_backtrace
+    assert_separately([], "#{<<-"begin;"}\n#{<<-"end;"}")
+    begin;
+      class Exception
+        undef backtrace
+      end
+
+      assert_raise(RuntimeError) {
+        raise RuntimeError, "hello"
+      }
+    end;
+  end
 end