merge master -> slot-runtime-hasupdatemethod and add a test

src/compile/render-dom/wrappers/Slot.ts

@@ -141,7 +141,7 @@ export default class SlotWrapper extends Wrapper {
 		if (this.dependencies.size > 1) update_conditions = `(${update_conditions})`;
 
 		block.builders.update.addBlock(deindent`
-			if (${slot} && ${update_conditions}) {
+			if (${slot} && ${slot}.p && ${update_conditions}) {
 				${slot}.p(@get_slot_changes(${slot_definition}, ctx, changed, ${get_slot_changes}), @get_slot_context(${slot_definition}, ctx, ${get_slot_context}));
 			}
 		`);
@@ -150,4 +150,4 @@ export default class SlotWrapper extends Wrapper {
 			`if (${slot}) ${slot}.d(detach);`
 		);
 	}
-}
+}

test/runtime/samples/component-slot-static-and-dynamic/Nested.svelte

@@ -0,0 +1,4 @@
+<div>
+	<slot name="a"></slot>
+	<slot name="b"></slot>
+</div>

test/runtime/samples/component-slot-static-and-dynamic/_config.js

@@ -0,0 +1,19 @@
+export default {
+	html: `
+		<div>
+			<span slot="a">static</span>
+			<span slot="b">0</span>
+		</div>
+	`,
+
+	test({ assert, component, target }) {
+		component.dynamic += 1;
+
+		assert.htmlEqual(target.innerHTML, `
+			<div>
+				<span slot="a">static</span>
+				<span slot="b">1</span>
+			</div>
+		`);
+	}
+};

test/runtime/samples/component-slot-static-and-dynamic/main.svelte

@@ -0,0 +1,11 @@
+<script>
+	import Nested from "./Nested.svelte";
+
+	export let dynamic = 0;
+</script>
+
+
+<Nested>
+	<span slot="a">static</span>
+	<span slot="b">{dynamic}</span>
+</Nested>