fix

Author: dummdidumm

packages/svelte/src/internal/client/reactivity/props.js

@@ -169,7 +169,7 @@ const spread_props_handler = {
 	has(target, key) {
 		for (let p of target.props) {
 			if (is_function(p)) p = p();
-			if (p != null && (key in p)) return true;
+			if (p != null && key in p) return true;
 		}
 
 		return false;

packages/svelte/tests/runtime-legacy/samples/prop-p-is-null/_config.js

@@ -0,0 +1,5 @@
+import { test } from '../../test';
+
+export default test({
+	html: '0 0'
+});