fix: allow redirects to external URLs from within form functions (#14329)

Fixes #14035

No test because weird to test using playwright, a comment should do

Author: dummdidumm

.changeset/quiet-chairs-flow.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+fix: allow redirects to external URLs from within form functions

packages/kit/src/runtime/client/client.js

@@ -440,7 +440,7 @@ function persist_state() {
  * @param {number} redirect_count
  * @param {{}} [nav_token]
  */
-async function _goto(url, options, redirect_count, nav_token) {
+export async function _goto(url, options, redirect_count, nav_token) {
 	/** @type {string[]} */
 	let query_keys;
 	const result = await navigate({

packages/kit/src/runtime/client/remote-functions/form.svelte.js

@@ -9,7 +9,7 @@ import {
 	app,
 	remote_responses,
 	started,
-	goto,
+	_goto,
 	set_nearest_error_page,
 	invalidateAll
 } from '../client.js';
@@ -102,7 +102,8 @@ export function form(id) {
 						if (!invalidateAll) {
 							refresh_queries(refreshes, updates);
 						}
-						void goto(form_result.location, { invalidateAll });
+						// Use internal version to allow redirects to external URLs
+						void _goto(form_result.location, { invalidateAll }, 0);
 					} else {
 						result = undefined;
 						throw new HttpError(500, form_result.error);