merge revision(s) 57510,57511: [Backport #13176]

	eval.c: hide internal objects

	* eval.c (rb_ensure): veil internal exception objects not to leak
	  in ensure functions.  [ruby-core:79371] [Bug #13176]
	ensured.c: fix conflict

	* ext/-test-/exception/ensured.c (exc_raise): get rid of conflict
	  with raise(2) in the standard.  [ruby-core:79371] [Bug #13176]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@57885 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

4 files changed, 37 insertions, 2 deletions

diff --git a/eval.c b/eval.c
index 4c6e8e98b4..62509688e3 100644
--- a/eval.c
+++ b/eval.c
@@ -913,7 +913,7 @@ rb_ensure(VALUE (*b_proc)(ANYARGS), VALUE data1, VALUE (*e_proc)(ANYARGS), VALUE
 {
     int state;
     volatile VALUE result = Qnil;
-    volatile VALUE errinfo;
+    VALUE errinfo;
     rb_thread_t *const th = GET_THREAD();
     rb_ensure_list_t ensure_list;
     ensure_list.entry.marker = 0;
@@ -927,6 +927,9 @@ rb_ensure(VALUE (*b_proc)(ANYARGS), VALUE data1, VALUE (*e_proc)(ANYARGS), VALUE
     }
     TH_POP_TAG();
     errinfo = th->errinfo;
+    if (!NIL_P(errinfo) && !RB_TYPE_P(errinfo, T_OBJECT)) {
+	th->errinfo = Qnil;
+    }
     th->ensure_list=ensure_list.next;
     (*ensure_list.entry.e_proc)(ensure_list.entry.data2);
     th->errinfo = errinfo;
diff --git a/ext/-test-/exception/ensured.c b/ext/-test-/exception/ensured.c
index 365e1f4f79..7dcc9b78ef 100644
--- a/ext/-test-/exception/ensured.c
+++ b/ext/-test-/exception/ensured.c
@@ -18,8 +18,22 @@ ensured(VALUE module, VALUE object)
     return rb_ensure(begin, object, ensure, object);
 }
 
+static VALUE
+exc_raise(VALUE exc)
+{
+    rb_exc_raise(exc);
+    return Qnil;
+}
+
+static VALUE
+ensure_raise(VALUE module, VALUE object, VALUE exc)
+{
+    return rb_ensure(rb_yield, object, exc_raise, exc);
+}
+
 void
 Init_ensured(VALUE klass)
 {
     rb_define_module_function(klass, "ensured", ensured, 1);
+    rb_define_module_function(klass, "ensure_raise", ensure_raise, 2);
 }
diff --git a/test/-ext-/exception/test_exception_at_throwing.rb b/test/-ext-/exception/test_exception_at_throwing.rb
new file mode 100644
index 0000000000..aba26079eb
--- /dev/null
+++ b/test/-ext-/exception/test_exception_at_throwing.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+require 'test/unit'
+
+module Bug
+  class TestException < Test::Unit::TestCase
+    def test_exception_at_throwing
+      assert_separately(%w[-r-test-/exception], "#{<<-"begin;"}\n#{<<-"end;"}")
+      begin;
+        e = RuntimeError.new("[Bug #13176]")
+        assert_raise_with_message(e.class, e.message) do
+          catch do |t|
+            Bug::Exception.ensure_raise(nil, e) {throw t}
+          end
+        end
+      end;
+    end
+  end
+end
diff --git a/version.h b/version.h
index 4a11b654ad..c65e0913ed 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.4.0"
 #define RUBY_RELEASE_DATE "2017-03-12"
-#define RUBY_PATCHLEVEL 49
+#define RUBY_PATCHLEVEL 50
 
 #define RUBY_RELEASE_YEAR 2017
 #define RUBY_RELEASE_MONTH 3