net.http.server: Support setting Content-Type of uncaught HTTP errors mod_http_errors normally sets the Content-Type header via the response object, which isn't available when handling these uncaught errors. Without a Content-Type header the browser is forced to guess, which may or may not result in something sensible.

author: Kim Alvefur <zash@zash.se>
date: Fri, 22 Sep 2023 01:47:21 +0200
parent: 13118:6b5e92949051
child: 13261:7c62370dee9a
--- a/net/http/server.lua	Sat Sep 16 14:23:08 2023 +0200
+++ b/net/http/server.lua	Fri Sep 22 01:47:21 2023 +0200
@@ -107,7 +107,12 @@
 
 function runner_callbacks:error(err)
 	log("error", "Traceback[httpserver]: %s", err);
-	self.data.conn:write("HTTP/1.0 500 Internal Server Error\r\n\r\n"..events.fire_event("http-error", { code = 500, private_message = err }));
+	local response = { headers = { content_type = "text/plain" }; body = "" };
+	response.body = events.fire_event("http-error", { code = 500; private_message = err; response = response });
+	self.data.conn:write("HTTP/1.0 500 Internal Server Error\r\n\z\
+		X-Content-Type-Options: nosniff\r\n\z\
+		Content-Type: " .. response.header.content_type .. "\r\n\r\n");
+	self.data.conn:write(response.body);
 	self.data.conn:close();
 end