From f3ceb0503375dbf02d8f9e6ece3a3ace1ebe7b9f Mon Sep 17 00:00:00 2001
From: Juliusz Chroboczek <jch@irif.fr>
Date: Thu, 9 May 2024 17:43:18 +0200
Subject: [PATCH] Add Accept header to 415 replies.

Also fix return code in WHIP.
---
 webserver/api.go  | 3 +++
 webserver/whip.go | 8 ++++++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/webserver/api.go b/webserver/api.go
index 8dc1c38..61461e4 100644
--- a/webserver/api.go
+++ b/webserver/api.go
@@ -75,6 +75,7 @@ func sendJSON(w http.ResponseWriter, r *http.Request, v any) {
 func getText(w http.ResponseWriter, r *http.Request) ([]byte, bool) {
 	ctype := parseContentType(r.Header.Get("Content-Type"))
 	if !strings.EqualFold(ctype, "text/plain") {
+		w.Header().Set("Accept", "text/plain")
 		http.Error(w, "unsupported content type",
 			http.StatusUnsupportedMediaType)
 		return nil, true
@@ -92,6 +93,7 @@ func getText(w http.ResponseWriter, r *http.Request) ([]byte, bool) {
 func getJSON(w http.ResponseWriter, r *http.Request, v any) bool {
 	ctype := parseContentType(r.Header.Get("Content-Type"))
 	if !strings.EqualFold(ctype, "application/json") {
+		w.Header().Set("Accept", "application/json")
 		http.Error(w, "unsupported content type",
 			http.StatusUnsupportedMediaType)
 		return true
@@ -458,6 +460,7 @@ func keysHandler(w http.ResponseWriter, r *http.Request, g string) {
 		// cannot use getJSON due to the weird content-type
 		ctype := parseContentType(r.Header.Get("Content-Type"))
 		if !strings.EqualFold(ctype, "application/jwk-set+json") {
+			w.Header().Set("Accept", "application/jwk-set+json")
 			http.Error(w, "unsupported content type",
 				http.StatusUnsupportedMediaType)
 			return
diff --git a/webserver/whip.go b/webserver/whip.go
index 5d7f5a9..2838375 100644
--- a/webserver/whip.go
+++ b/webserver/whip.go
@@ -192,7 +192,9 @@ func whipEndpointHandler(w http.ResponseWriter, r *http.Request) {
 
 	ctype := r.Header.Get("content-type")
 	if !strings.EqualFold(ctype, "application/sdp") {
-		http.Error(w, "bad content type", http.StatusBadRequest)
+		w.Header().Set("Accept", "application/sdp")
+		http.Error(w, "bad content type",
+			http.StatusUnsupportedMediaType)
 		return
 	}
 
@@ -337,7 +339,9 @@ func whipResourceHandler(w http.ResponseWriter, r *http.Request) {
 
 	ctype := r.Header.Get("content-type")
 	if !strings.EqualFold(ctype, "application/trickle-ice-sdpfrag") {
-		http.Error(w, "bad content type", http.StatusBadRequest)
+		w.Header().Set("Accept", "application/trickle-ice-sdpfrag")
+		http.Error(w, "bad content type",
+			http.StatusUnsupportedMediaType)
 		return
 	}