tweak

packages/svelte/src/internal/client/reactivity/batch.js

@@ -411,10 +411,12 @@ export class Batch {
 		// causing an effect and therefore a root to be scheduled again. We need to traverse the current batch
 		// once more in that case - most of the time this will just clean up dirty branches.
 		if (this.#roots.length > 0) {
-			next_batch ??= this;
-
-			const batch = next_batch;
-			batch.#roots.push(...this.#roots.filter((r) => !batch.#roots.includes(r)));
+			if (next_batch !== null) {
+				const batch = next_batch;
+				batch.#roots.push(...this.#roots.filter((r) => !batch.#roots.includes(r)));
+			} else {
+				next_batch = this;
+			}
 		}
 
 		if (next_batch !== null) {