reinstate standalone optimisation

packages/svelte/src/compiler/phases/3-transform/server/transform-server.js

@@ -1025,7 +1025,7 @@ function serialize_inline_component(node, expression, context) {
 		context.state.template.push(statement);
 	}
 
-	if (custom_css_props.length === 0) {
+	if (custom_css_props.length === 0 && !context.state.skip_hydration_boundaries) {
 		context.state.template.push(block_close);
 	}
 }
@@ -1219,7 +1219,9 @@ const template_visitors = {
 			)
 		);
 
+		if (!context.state.skip_hydration_boundaries) {
 			context.state.template.push(block_close);
+		}
 	},
 	ClassDirective() {
 		throw new Error('Node should have been handled elsewhere');

packages/svelte/src/compiler/phases/3-transform/utils.js

@@ -291,7 +291,7 @@ export function clean_nodes(
 		first &&
 		(first?.type === 'Text' || first?.type === 'ExpressionTag');
 
-	return { hoisted, trimmed, is_standalone: false, is_anchored };
+	return { hoisted, trimmed, is_standalone, is_anchored };
 }
 
 /**

packages/svelte/tests/snapshot/samples/bind-this/_expected/client/index.svelte.js

@@ -2,9 +2,5 @@ import "svelte/internal/disclose-version";
 import * as $ from "svelte/internal/client";
 
 export default function Bind_this($$anchor) {
-	var fragment = $.comment();
-	var node = $.first_child(fragment);
-
-	$.bind_this(Foo(node, { $$legacy: true }), ($$value) => foo = $$value, () => foo);
-	$.append($$anchor, fragment);
+	$.bind_this(Foo($$anchor, { $$legacy: true }), ($$value) => foo = $$value, () => foo);
 }

packages/svelte/tests/snapshot/samples/bind-this/_expected/server/index.svelte.js

@@ -2,5 +2,4 @@ import * as $ from "svelte/internal/server";
 
 export default function Bind_this($$payload) {
 	Foo($$payload, {});
-	$$payload.out += `<!--]-->`;
 }

packages/svelte/tests/snapshot/samples/function-prop-no-getter/_expected/client/index.svelte.js

@@ -9,10 +9,8 @@ export default function Function_prop_no_getter($$anchor) {
 	}
 
 	const plusOne = (num) => num + 1;
-	var fragment = $.comment();
-	var node = $.first_child(fragment);
 
-	Button(node, {
+	Button($$anchor, {
 		onmousedown: () => $.set(count, $.get(count) + 1),
 		onmouseup,
 		onmouseenter: () => $.set(count, $.proxy(plusOne($.get(count)))),
@@ -24,6 +22,4 @@ export default function Function_prop_no_getter($$anchor) {
 		},
 		$$slots: { default: true }
 	});
-
-	$.append($$anchor, fragment);
 }

packages/svelte/tests/snapshot/samples/function-prop-no-getter/_expected/server/index.svelte.js

@@ -18,6 +18,4 @@ export default function Function_prop_no_getter($$payload) {
 		},
 		$$slots: { default: true }
 	});
-
-	$$payload.out += `<!--]-->`;
 }