fix: allow get_proxied_value to return original value when error (sveltejs#15577)

* fix: allow get_proxied_value to return original value when error closes sveltejs#15546 * Update packages/svelte/src/internal/client/proxy.js --------- Co-authored-by: Rich Harris <hello@rich-harris.dev>

Author: crookedneighbor

.changeset/afraid-penguins-battle.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: prevent dev server from throwing errors when attempting to retrieve the proxied value of an iframe's contentWindow

packages/svelte/src/internal/client/proxy.js

@@ -366,8 +366,18 @@ function update_version(signal, d = 1) {
  * @param {any} value
  */
 export function get_proxied_value(value) {
-if (value !== null && typeof value === 'object' && STATE_SYMBOL in value) {
-return value[STATE_SYMBOL];
+try {
+if (value !== null && typeof value === 'object' && STATE_SYMBOL in value) {
+return value[STATE_SYMBOL];
+}
+} catch {
+// the above if check can throw an error if the value in question
+// is the contentWindow of an iframe on another domain, in which
+// case we want to just return the value (because it's definitely
+// not a proxied value) so we don't break any JavaScript interacting
+// with that iframe (such as various payment companies client side
+// JavaScript libraries interacting with their iframes on the same
+// domain)
 }
 
 return value;