From 110778457ba562273ec73279d4e16aff906492b4 Mon Sep 17 00:00:00 2001
From: Artem Zhirov <mail@azhirov.ru>
Date: Wed, 4 Sep 2024 01:55:39 +0500
Subject: [PATCH] Fix: prevent island re-rendering when using
 transition:persist (#11854)

https://github.com/withastro/astro/issues/11854
---
 .changeset/seven-bees-love.md                    | 5 +++++
 packages/astro/src/transitions/swap-functions.ts | 6 +++++-
 2 files changed, 10 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/seven-bees-love.md

diff --git a/.changeset/seven-bees-love.md b/.changeset/seven-bees-love.md
new file mode 100644
index 0000000000000..f1305c9822f6b
--- /dev/null
+++ b/.changeset/seven-bees-love.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fix: prevent island from re-rendering when using transition:persist (#11854)
diff --git a/packages/astro/src/transitions/swap-functions.ts b/packages/astro/src/transitions/swap-functions.ts
index e2d8557f5d500..23d62b4a0b84d 100644
--- a/packages/astro/src/transitions/swap-functions.ts
+++ b/packages/astro/src/transitions/swap-functions.ts
@@ -77,7 +77,7 @@ export function swapBodyElement(newElement: Element, oldElement: Element) {
 			// from the old page so that state is preserved.
 			newEl.replaceWith(el);
 			// For islands, copy over the props to allow them to re-render
-			if (newEl.localName === 'astro-island' && shouldCopyProps(el as HTMLElement)) {
+			if (newEl.localName === 'astro-island' && shouldCopyProps(el as HTMLElement) && !isSameProps(el, newEl)) {
 				el.setAttribute('ssr', '');
 				el.setAttribute('props', newEl.getAttribute('props')!);
 			}
@@ -133,6 +133,10 @@ const shouldCopyProps = (el: HTMLElement): boolean => {
 	return persistProps == null || persistProps === 'false';
 };
 
+const isSameProps = (oldEl: Element, newEl: Element) => {
+	return oldEl.getAttribute('props') === newEl.getAttribute('props')
+}
+
 export const swapFunctions = {
 	deselectScripts,
 	swapRootAttributes,