Fix headAsGetHandler

cache.go

@@ -94,7 +94,7 @@ func (a *goBlog) cacheMiddleware(next http.Handler) http.Handler {
 }
 
 func cacheable(r *http.Request) bool {
-	if !(r.Method == http.MethodGet || r.Method == http.MethodHead) {
+	if r.Method != http.MethodGet && r.Method != http.MethodHead {
 		return false
 	}
 	if r.URL.Query().Get("cache") == "0" || r.URL.Query().Get("cache") == "false" {

http.go

@@ -46,7 +46,7 @@ func (a *goBlog) startServer() (err error) {
 	compressor.SetEncoder("br", func(w io.Writer, _ int) io.Writer {
 		return brotli.NewWriter(w)
 	})
-	h = h.Append(middleware.Recoverer, compressor.Handler, middleware.Heartbeat("/ping"), headAsGetHandler)
+	h = h.Append(middleware.Recoverer, compressor.Handler, middleware.Heartbeat("/ping"))
 	if a.httpsConfigured(false) {
 		h = h.Append(a.securityHeaders)
 	}
@@ -225,7 +225,7 @@ func (a *goBlog) buildRouter() (http.Handler, error) {
 	r.MethodNotAllowed(a.serveNotAllowed)
 
 	mapRouter.DefaultHandler = r
-	return mapRouter, nil
+	return alice.New(headAsGetHandler).Then(mapRouter), nil
 }
 
 func (a *goBlog) servePostsAliasesRedirects() http.HandlerFunc {

httpMiddlewares.go

@@ -23,7 +23,13 @@ func fixHTTPHandler(next http.Handler) http.Handler {
 func headAsGetHandler(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if r.Method == http.MethodHead {
-			r.Method = http.MethodGet
+			// Clone request and change method
+			newReq := new(http.Request)
+			*newReq = *r
+			newReq.Method = http.MethodGet
+			// Serve new request
+			next.ServeHTTP(w, newReq)
+			return
 		}
 		next.ServeHTTP(w, r)
 	})