Tests: Ruby module.

test/ruby/errors_write_to_s_custom/config.ru

@@ -0,0 +1,15 @@
+app = Proc.new do |env|
+
+    class Custom
+        def to_s()
+            nil
+        end
+    end
+
+    e = Custom.new()
+
+    env['rack.errors'].write(e)
+    ['200', {'Content-Length' => '0'}, ['']]
+end
+
+run app