error.c: check redefined backtrace result

* error.c (rb_get_backtrace): check the result of `backtrace` even
  if the method is redefined.  [ruby-core:87013] [Bug #14756]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63417 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 10 insertions, 0 deletions

diff --git a/test/ruby/test_exception.rb b/test/ruby/test_exception.rb
index 8dafa45120..fddb0f3a0f 100644
--- a/test/ruby/test_exception.rb
+++ b/test/ruby/test_exception.rb
@@ -1236,6 +1236,16 @@ $stderr = $stdout; raise "\x82\xa0"') do |outs, errs, status|
         raise RuntimeError, "hello"
       }
     end;
+
+    error_class = Class.new(StandardError) do
+      def backtrace; :backtrace; end
+    end
+    begin
+      raise error_class
+    rescue error_class => e
+      assert_raise(TypeError) {$@}
+      assert_raise(TypeError) {e.full_message}
+    end
   end
 
   def test_backtrace_in_eval