only apply key to keyed each block, not its children - fixes #1202

src/generators/dom/Block.ts

@@ -163,7 +163,7 @@ export default class Block {
 	}
 
 	child(options: BlockOptions) {
-		return new Block(Object.assign({}, this, options, { parent: this }));
+		return new Block(Object.assign({}, this, { key: null }, options, { parent: this }));
 	}
 
 	contextualise(expression: Node, context?: string, isEventHandler?: boolean) {

test/runtime/samples/if-in-keyed-each/_config.js

@@ -0,0 +1,15 @@
+export default {
+	data: {
+		items: [
+			{ id: 1, name: 'one' },
+			{ id: 2, name: 'two' }
+		]
+	},
+
+	html: `
+		<ul>
+			<li>one</li>
+			<li>two</li>
+		</ul>
+	`
+};

test/runtime/samples/if-in-keyed-each/main.html

@@ -0,0 +1,7 @@
+<ul>
+	{{#each items as item @id}}
+		{{#if item.id}}
+			<li>{{item.name}}</li>
+		{{/if}}
+	{{/each}}
+</ul>