fix: infinite loop when binding object in key block

src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts

@@ -309,6 +309,9 @@ export default class InlineComponentWrapper extends Wrapper {
 				}`);
 		}
 
+
+		const is_key_block_child = this.parent && this.parent.node.type === 'KeyBlock';
+		const key_called = '_called';
 		const munged_bindings = this.node.bindings.map(binding => {
 			component.has_reactive_assignments = true;
 
@@ -397,7 +400,8 @@ export default class InlineComponentWrapper extends Wrapper {
 
 			component.partly_hoisted.push(body);
 
-			return b`@binding_callbacks.push(() => @bind(${this.var}, '${binding.name}', ${id}));`;
+			const run_call_back = is_key_block_child && x`!${block.name}.${key_called}`;
+			return b`@binding_callbacks.push(() => @bind(${this.var}, '${binding.name}', ${id}, ${run_call_back}));`;
 		});
 
 		const munged_handlers = this.node.handlers.map(handler => {
@@ -523,9 +527,9 @@ export default class InlineComponentWrapper extends Wrapper {
 				${props && b`let ${props} = ${attribute_object};`}`}
 				${statements}
 				${name} = new ${expression}(${component_opts});
-
 				${munged_bindings}
 				${munged_handlers}
+				${is_key_block_child && x`${block.name}.${key_called} = true`}
 			`);
 
 			if (has_css_custom_properties) {

src/runtime/internal/Component.ts

@@ -5,13 +5,15 @@ import { children, detach, start_hydrating, end_hydrating } from './dom';
 import { transition_in } from './transitions';
 import { T$$ } from './types';
 
-export function bind(component, name, callback) {
+export function bind(component, name, callback, runCallback = true) {
 	const index = component.$$.props[name];
 	if (index !== undefined) {
 		component.$$.bound[index] = callback;
+		if (runCallback) {
 			callback(component.$$.ctx[index]);
 		}
 	}
+}
 
 export function create_component(block) {
 	block && block.c();

test/runtime/samples/binding-object-in-key-block/Component.svelte

@@ -0,0 +1,7 @@
+<script lang='ts'>
+	export let obj;
+</script>
+
+<p>
+	{obj.value}
+</p>

test/runtime/samples/binding-object-in-key-block/_config.js

@@ -0,0 +1,4 @@
+// fix: https://github.com/sveltejs/svelte/issues/8305
+export default {
+	html: '<p>0</p>'
+};

test/runtime/samples/binding-object-in-key-block/main.svelte

@@ -0,0 +1,10 @@
+<script>
+	import Component from './Component.svelte';
+	let obj = {
+		value: '0'
+	};
+</script>
+
+{#key obj}
+	<Component bind:obj={obj} />
+{/key}