From 00767fe8e23aad9d84c0aff6c87cadcb055439ea Mon Sep 17 00:00:00 2001
From: Richard Harris <richard.a.harris@gmail.com>
Date: Mon, 18 May 2020 20:53:14 -0400
Subject: [PATCH] alternative fix for #4693

---
 src/compiler/compile/render_dom/Block.ts      | 21 ++++++++++++-------
 .../Component.svelte                          |  5 +++++
 .../_config.js                                | 21 +++++++++++++++++++
 .../main.svelte                               | 17 +++++++++++++++
 4 files changed, 57 insertions(+), 7 deletions(-)
 create mode 100644 test/runtime/samples/each-block-keyed-component-action/Component.svelte
 create mode 100644 test/runtime/samples/each-block-keyed-component-action/_config.js
 create mode 100644 test/runtime/samples/each-block-keyed-component-action/main.svelte

diff --git a/src/compiler/compile/render_dom/Block.ts b/src/compiler/compile/render_dom/Block.ts
index b29b4d4afd95..b77cf6111253 100644
--- a/src/compiler/compile/render_dom/Block.ts
+++ b/src/compiler/compile/render_dom/Block.ts
@@ -299,7 +299,7 @@ export default class Block {
 				${this.chunks.mount}
 			}`;
 		} else {
-			properties.mount = x`function #mount(#target, #anchor, #remount) {
+			properties.mount = x`function #mount(#target, #anchor) {
 				${this.chunks.mount}
 			}`;
 		}
@@ -452,6 +452,9 @@ export default class Block {
 
 	render_listeners(chunk: string = '') {
 		if (this.event_listeners.length > 0) {
+			this.add_variable({ type: 'Identifier', name: '#mounted' });
+			this.chunks.destroy.push(b`#mounted = false`);
+
 			const dispose: Identifier = {
 				type: 'Identifier',
 				name: `#dispose${chunk}`
@@ -462,8 +465,10 @@ export default class Block {
 			if (this.event_listeners.length === 1) {
 				this.chunks.mount.push(
 					b`
-						if (#remount) ${dispose}();
-						${dispose} = ${this.event_listeners[0]};
+						if (!#mounted) {
+							${dispose} = ${this.event_listeners[0]};
+							#mounted = true;
+						}
 					`
 				);
 
@@ -472,10 +477,12 @@ export default class Block {
 				);
 			} else {
 				this.chunks.mount.push(b`
-					if (#remount) @run_all(${dispose});
-					${dispose} = [
-						${this.event_listeners}
-					];
+					if (!#mounted) {
+						${dispose} = [
+							${this.event_listeners}
+						];
+						#mounted = true;
+					}
 				`);
 
 				this.chunks.destroy.push(
diff --git a/test/runtime/samples/each-block-keyed-component-action/Component.svelte b/test/runtime/samples/each-block-keyed-component-action/Component.svelte
new file mode 100644
index 000000000000..18a6c7452a01
--- /dev/null
+++ b/test/runtime/samples/each-block-keyed-component-action/Component.svelte
@@ -0,0 +1,5 @@
+<script>
+	export let action;
+</script>
+
+<div use:action />
diff --git a/test/runtime/samples/each-block-keyed-component-action/_config.js b/test/runtime/samples/each-block-keyed-component-action/_config.js
new file mode 100644
index 000000000000..c4421f89aea2
--- /dev/null
+++ b/test/runtime/samples/each-block-keyed-component-action/_config.js
@@ -0,0 +1,21 @@
+export default {
+	test({ assert, component, raf }) {
+		assert.equal(component.count, 0);
+
+		component.arr = ["2"];
+
+		assert.equal(component.count, 1);
+
+		component.arr = ["1", "2"];
+
+		assert.equal(component.count, 2);
+
+		component.arr = ["2", "1"];
+
+		assert.equal(component.count, 2);
+
+		component.arr = [];
+
+		assert.equal(component.count, 0);
+	},
+};
diff --git a/test/runtime/samples/each-block-keyed-component-action/main.svelte b/test/runtime/samples/each-block-keyed-component-action/main.svelte
new file mode 100644
index 000000000000..bfacdf402a02
--- /dev/null
+++ b/test/runtime/samples/each-block-keyed-component-action/main.svelte
@@ -0,0 +1,17 @@
+<script>
+	import Component from "./Component.svelte";
+	export let arr = [];
+	export let count = 0;
+	function action(node, params) {
+		count += 1;
+		return {
+			destroy() {
+				count -= 1;
+			}
+		};
+	}
+</script>
+
+{#each arr as item (item)}
+	<Component {action} />
+{/each}