From e1cfa14f938673635200289dd2832fed68b73a39 Mon Sep 17 00:00:00 2001
From: Dominic Gannaway <dg@domgan.com>
Date: Tue, 28 Nov 2023 15:28:59 +0000
Subject: [PATCH] check visited for cyclical values

---
 packages/svelte/src/internal/client/runtime.js | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/packages/svelte/src/internal/client/runtime.js b/packages/svelte/src/internal/client/runtime.js
index ba47613426..ce2500b577 100644
--- a/packages/svelte/src/internal/client/runtime.js
+++ b/packages/svelte/src/internal/client/runtime.js
@@ -1800,12 +1800,14 @@ export function pop(accessors) {
 
 /**
  * @param {any} value
+ * @param {Set<any>} visited
  * @returns {void}
  */
-function deep_read(value) {
-	if (typeof value === 'object' && value !== null) {
+function deep_read(value, visited = new Set()) {
+	if (typeof value === 'object' && value !== null && !visited.has(value)) {
+		visited.add(value);
 		for (let key in value) {
-			deep_read(value[key]);
+			deep_read(value[key], visited);
 		}
 		const proto = Object.getPrototypeOf(value);
 		if (