From b799868c3c4ed8bfd250dc6d4603a3982034fa6b Mon Sep 17 00:00:00 2001
From: Dominic Gannaway <dg@domgan.com>
Date: Thu, 1 Feb 2024 09:53:28 +0000
Subject: [PATCH] more fixes

---
 packages/svelte/src/internal/client/proxy.js   | 14 +++++++++++++-
 packages/svelte/src/internal/client/runtime.js |  8 ++++----
 packages/svelte/src/internal/client/types.d.ts |  1 +
 3 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/packages/svelte/src/internal/client/proxy.js b/packages/svelte/src/internal/client/proxy.js
index 07003a193d..72190f9679 100644
--- a/packages/svelte/src/internal/client/proxy.js
+++ b/packages/svelte/src/internal/client/proxy.js
@@ -8,7 +8,10 @@ import {
 	updating_derived,
 	UNINITIALIZED,
 	mutable_source,
-	batch_inspect
+	batch_inspect,
+	current_derived_property_access,
+	effect_active_and_not_render_effect,
+	is_primitive_or_function_or_state_object
 } from './runtime.js';
 import {
 	array_prototype,
@@ -197,6 +200,15 @@ const state_proxy_handler = {
 		}
 
 		if (s !== undefined) {
+			if (
+				current_derived_property_access !== null &&
+				current_derived_property_access.v === receiver &&
+				(effect_active_and_not_render_effect() || updating_derived) &&
+				is_primitive_or_function_or_state_object(s.v)
+			) {
+				current_derived_property_access.v = s.v;
+				current_derived_property_access.p.push(prop);
+			}
 			const value = get(s);
 			return value === UNINITIALIZED ? undefined : value;
 		}
diff --git a/packages/svelte/src/internal/client/runtime.js b/packages/svelte/src/internal/client/runtime.js
index 0ecd18de02..2364e91029 100644
--- a/packages/svelte/src/internal/client/runtime.js
+++ b/packages/svelte/src/internal/client/runtime.js
@@ -62,7 +62,7 @@ let current_queued_effects = [];
 /**
  * @type {import('./types.js').DerivedPropertyAccess | null}
  */
-let current_derived_property_access = null;
+export let current_derived_property_access = null;
 
 /** @type {Array<() => void>} */
 let current_queued_tasks = [];
@@ -1452,7 +1452,7 @@ function proxify_object(signal, value, handler, path) {
 /**
  * @param {any} value
  */
-function is_primitive_or_function_or_state_object(value) {
+export function is_primitive_or_function_or_state_object(value) {
 	const type = typeof value;
 	return (
 		value == null ||
@@ -1505,7 +1505,7 @@ function create_derived_proxy(signal, derived_value) {
 					if (current_derived_property_access !== null) {
 						capture_derived_property_access(current_derived_property_access);
 					} else {
-						current_derived_property_access = { s: signal, p: new_path };
+						current_derived_property_access = { s: signal, p: new_path, v: value };
 					}
 				}
 				if (should_proxy_derived_value(value)) {
@@ -1614,7 +1614,7 @@ export function effect_active() {
 /**
  * @returns {boolean}
  */
-function effect_active_and_not_render_effect() {
+export function effect_active_and_not_render_effect() {
 	return current_effect ? (current_effect.f & (MANAGED | RENDER_EFFECT)) === 0 : false;
 }
 
diff --git a/packages/svelte/src/internal/client/types.d.ts b/packages/svelte/src/internal/client/types.d.ts
index 1edc2e99a0..f0578371ae 100644
--- a/packages/svelte/src/internal/client/types.d.ts
+++ b/packages/svelte/src/internal/client/types.d.ts
@@ -130,6 +130,7 @@ export type ComputationSignal<V = unknown> = {
 export type DerivedPropertyAccess = {
 	s: ComputationSignal;
 	p: Array<string | symbol>;
+	v: any;
 };
 
 export type Signal<V = unknown> = SourceSignal<V> | ComputationSignal<V>;