From 37d270b21fb56810d7d433cce0ac2b50531bdf6b Mon Sep 17 00:00:00 2001
From: Rich Harris <rich.harris@vercel.com>
Date: Thu, 26 Feb 2026 15:58:38 -0500
Subject: [PATCH] WIP

---
 .../src/internal/client/reactivity/batch.js   | 35 ++++++++++++++++---
 1 file changed, 31 insertions(+), 4 deletions(-)

diff --git a/packages/svelte/src/internal/client/reactivity/batch.js b/packages/svelte/src/internal/client/reactivity/batch.js
index eede5097f7..b75b629f57 100644
--- a/packages/svelte/src/internal/client/reactivity/batch.js
+++ b/packages/svelte/src/internal/client/reactivity/batch.js
@@ -524,19 +524,46 @@ export class Batch {
 	}
 
 	apply() {
+		if (!batches.has(this)) {
+			console.warn('wtf', this.id);
+		}
+
 		if (!async_mode_flag || (!this.is_fork && batches.size === 1)) return;
 
+		console.log(this.id, batches.size);
+
 		// if there are multiple batches, we are 'time travelling' —
 		// we need to override values with the ones in this batch...
 		batch_values = new Map(this.current);
 
+		var is_earlier = true;
+
 		// ...and undo changes belonging to other batches
+		// that don't coincide with this batch
 		for (const batch of batches) {
-			if (batch === this) continue;
+			if (batch === this) {
+				is_earlier = false;
+				continue;
+			}
+
+			var coincides = false;
 
-			for (const [source, previous] of batch.previous) {
-				if (!batch_values.has(source)) {
-					batch_values.set(source, previous);
+			if (is_earlier) {
+				for (const source of batch.current.keys()) {
+					if (this.current.has(source)) {
+						coincides = true;
+						break;
+					}
+				}
+			}
+
+			console.log(batch.id, { coincides });
+
+			if (!coincides) {
+				for (const [source, previous] of batch.previous) {
+					if (!batch_values.has(source)) {
+						batch_values.set(source, previous);
+					}
 				}
 			}
 		}