add req header to identify chain request

Author: teemingc

packages/kit/src/runtime/server/page/respond_with_error.js

@@ -28,6 +28,11 @@ export async function respond_with_error({
 	error,
 	resolve_opts
 }) {
+	// reroute to the fallback page to prevent an infinite chain of requests.
+	if (event.request.headers.get('x-sveltekit-error')) {
+		return static_error_page(options, status, /** @type {Error} */ (error).message);
+	}
+
 	/** @type {import('./types').Fetched[]} */
 	const fetched = [];
 

packages/kit/src/runtime/server/respond.js

@@ -457,8 +457,12 @@ export async function respond(request, options, manifest, state) {
 				return response;
 			}
 
-			if (state.error && state.depth > 0) {
-				return await fetch(request);
+			if (state.error && event.isSubRequest) {
+				return await fetch(request, {
+					headers: {
+						'x-sveltekit-error': 'true'
+					}
+				});
 			}
 
 			if (state.error) {

packages/kit/test/apps/basics/src/routes/+layout.server.js

@@ -18,10 +18,7 @@ export async function load({ cookies, locals, fetch }) {
 	}
 
 	if (locals.url?.pathname === '/non-existent-route-loop') {
-		await fetch('/non-existent-route-loop').then((r) => {
-			console.log(r.status);
-			return r.json();
-		});
+		await fetch('/non-existent-route-loop');
 	}
 
 	const should_fail = cookies.get('fail-type');