fix: reevaluate namespace in slots (#11849)

Closes #11847

Author: paoloricciuti

.changeset/shiny-months-tease.md

@@ -0,0 +1,5 @@
+---
+"svelte": patch
+---
+
+fix: reevaluate namespace in slots

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

@@ -176,7 +176,8 @@ export function infer_namespace(namespace, parent, nodes) {
 			parent.type === 'Component' ||
 			parent.type === 'SvelteComponent' ||
 			parent.type === 'SvelteFragment' ||
-			parent.type === 'SnippetBlock'
+			parent.type === 'SnippetBlock' ||
+			parent.type === 'SlotElement'
 		) {
 			const new_namespace = check_nodes_for_namespace(nodes, 'keep');
 			if (new_namespace !== 'keep' && new_namespace !== 'maybe_html') {

packages/svelte/tests/runtime-legacy/samples/slot-svg/_config.js

@@ -0,0 +1,9 @@
+import { ok, test } from '../../test';
+
+export default test({
+	async test({ assert, target }) {
+		const circle = target.querySelector('circle');
+		ok(circle);
+		assert.equal(circle.namespaceURI, 'http://www.w3.org/2000/svg');
+	}
+});

packages/svelte/tests/runtime-legacy/samples/slot-svg/main.svelte

@@ -0,0 +1,7 @@
+<script>
+	import Points from './points.svelte';
+</script>
+
+<svg>
+	<Points />
+</svg>

packages/svelte/tests/runtime-legacy/samples/slot-svg/points.svelte

@@ -0,0 +1,3 @@
+<slot>
+	<circle cx={10} cy={10} r={5} />
+</slot>