From 33b8910cfdce5713891c50a84a0a8fe926311710 Mon Sep 17 00:00:00 2001
From: Martin Trapp <94928215+martrapp@users.noreply.github.com>
Date: Thu, 17 Aug 2023 18:18:30 +0200
Subject: [PATCH] only update our own history entires during back navigation
 through view transitions (#8116)

---
 .changeset/small-nails-try.md                   | 5 +++++
 packages/astro/components/ViewTransitions.astro | 9 ++++++---
 2 files changed, 11 insertions(+), 3 deletions(-)
 create mode 100644 .changeset/small-nails-try.md

diff --git a/.changeset/small-nails-try.md b/.changeset/small-nails-try.md
new file mode 100644
index 000000000..3f6f591f1
--- /dev/null
+++ b/.changeset/small-nails-try.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+On back navigation only animate view transitions that were animated going forward.
diff --git a/packages/astro/components/ViewTransitions.astro b/packages/astro/components/ViewTransitions.astro
index 3967d0aee..4b7a46551 100644
--- a/packages/astro/components/ViewTransitions.astro
+++ b/packages/astro/components/ViewTransitions.astro
@@ -306,10 +306,11 @@ const { fallback = 'animate' } = Astro.props as Props;
 				return;
 			}
 
-			// hash change creates no state.
+			// History entries without state are created by the browser (e.g. for hash links)
+			// Our view transition entries always have state.
+			// Just ignore stateless entries.
+			// The browser will handle navigation fine without our help
 			if (ev.state === null) {
-				persistState({ index: currentHistoryIndex, scrollY });
-				ev.preventDefault();
 				return;
 			}
 
@@ -344,6 +345,8 @@ const { fallback = 'animate' } = Astro.props as Props;
 		addEventListener(
 			'scroll',
 			throttle(() => {
+				// only updste history entries that are managed by us
+				// leave other entries alone and do not accidently add state.
 				if (history.state) {
 					persistState({ ...history.state, scrollY });
 				}