From 385adf5d878939c381c7f73c771771d34523a1a7 Mon Sep 17 00:00:00 2001
From: Matt Holt <mholt@users.noreply.github.com>
Date: Tue, 13 Oct 2020 10:52:39 -0600
Subject: [PATCH] caddyhttp: Restore original request params before error
 handlers (#3781)

* caddyhttp: Restore original request params before error handlers

Fixes #3717

* Add comment
---
 modules/caddyhttp/server.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/modules/caddyhttp/server.go b/modules/caddyhttp/server.go
index 4f198e5d..aaec711c 100644
--- a/modules/caddyhttp/server.go
+++ b/modules/caddyhttp/server.go
@@ -209,6 +209,14 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// restore original request before invoking error handler chain (issue #3717)
+	// TODO: this does not restore original headers, if modified (for efficiency)
+	origReq := r.Context().Value(OriginalRequestCtxKey).(http.Request)
+	r.Method = origReq.Method
+	r.RemoteAddr = origReq.RemoteAddr
+	r.RequestURI = origReq.RequestURI
+	cloneURL(origReq.URL, r.URL)
+
 	// prepare the error log
 	logger := errLog
 	if s.Logs != nil {