From 32f43b125bd0900bbdd55948948d659cd2a84f2e Mon Sep 17 00:00:00 2001
From: Conduitry <git@chor.date>
Date: Sat, 30 Nov 2019 15:18:29 -0500
Subject: [PATCH] fix child context in await blocks with no `then` variable
 (#4022)

---
 .../compile/render_dom/wrappers/AwaitBlock.ts        |  4 ++--
 .../samples/await-then-no-context/main.svelte        | 12 ++++++++++++
 2 files changed, 14 insertions(+), 2 deletions(-)
 create mode 100644 test/runtime/samples/await-then-no-context/main.svelte

diff --git a/src/compiler/compile/render_dom/wrappers/AwaitBlock.ts b/src/compiler/compile/render_dom/wrappers/AwaitBlock.ts
index 8ce7495fd7..01153b1083 100644
--- a/src/compiler/compile/render_dom/wrappers/AwaitBlock.ts
+++ b/src/compiler/compile/render_dom/wrappers/AwaitBlock.ts
@@ -206,7 +206,7 @@ export default class AwaitBlockWrapper extends Wrapper {
 
 					} else {
 						const #child_ctx = #ctx.slice();
-						#child_ctx[${value_index}] = ${info}.resolved;
+						${this.node.value && x`#child_ctx[${value_index}] = ${info}.resolved;`}
 						${info}.block.p(#child_ctx, #dirty);
 					}
 				`);
@@ -220,7 +220,7 @@ export default class AwaitBlockWrapper extends Wrapper {
 				block.chunks.update.push(b`
 					{
 						const #child_ctx = #ctx.slice();
-						#child_ctx[${value_index}] = ${info}.resolved;
+						${this.node.value && x`#child_ctx[${value_index}] = ${info}.resolved;`}
 						${info}.block.p(#child_ctx, #dirty);
 					}
 				`);
diff --git a/test/runtime/samples/await-then-no-context/main.svelte b/test/runtime/samples/await-then-no-context/main.svelte
new file mode 100644
index 0000000000..c729512149
--- /dev/null
+++ b/test/runtime/samples/await-then-no-context/main.svelte
@@ -0,0 +1,12 @@
+<script>
+	const promise = new Promise(() => {});
+	const test = [1, 2, 3];
+</script>
+
+{#await promise}
+	<div>waiting</div>
+{:then}
+	{#each test as t}
+		<div>t</div>
+	{/each}
+{/await}