From 81e3d4305f060cc2ec8559251ff9739f9dec1fdc Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Wed, 1 Jul 2020 00:53:43 +0300
Subject: [PATCH] lib/httpserver: add Unwrap method to ErrorWithStatusCode, so
 `As` and `Is` functions in standard `errors` package may properly unwrap the
 error inside ErrorWithStatusCode

---
 lib/httpserver/httpserver.go | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/httpserver/httpserver.go b/lib/httpserver/httpserver.go
index 739b31d911..ca4f77f386 100644
--- a/lib/httpserver/httpserver.go
+++ b/lib/httpserver/httpserver.go
@@ -455,6 +455,13 @@ type ErrorWithStatusCode struct {
 	StatusCode int
 }
 
+// Unwrap returns e.Err.
+//
+// This is used by standard errors package. See https://golang.org/pkg/errors
+func (e *ErrorWithStatusCode) Unwrap() error {
+	return e.Err
+}
+
 // Error implements error interface.
 func (e *ErrorWithStatusCode) Error() string {
 	return e.Err.Error()