fix: allow bind:this on <select> with dynamic multiple attribute (#11378)

fixes #11377

Author: dummdidumm

.changeset/healthy-ants-film.md

@@ -0,0 +1,5 @@
+---
+"svelte": patch
+---
+
+fix: allow `bind:this` on `<select>` with dynamic `multiple` attribute

packages/svelte/src/compiler/phases/2-analyze/validation.js

@@ -413,7 +413,7 @@ const validation = {
 					}
 				}
 
-				if (parent.name === 'select') {
+				if (parent.name === 'select' && node.name !== 'this') {
 					const multiple = parent.attributes.find(
 						(a) =>
 							a.type === 'Attribute' &&

packages/svelte/tests/validator/samples/binding-select-multiple-dynamic/errors.json

@@ -3,11 +3,11 @@
 		"code": "attribute_invalid_multiple",
 		"message": "'multiple' attribute must be static if select uses two-way binding",
 		"start": {
-			"line": 6,
+			"line": 14,
 			"column": 19
 		},
 		"end": {
-			"line": 6,
+			"line": 14,
 			"column": 29
 		}
 	}

packages/svelte/tests/validator/samples/binding-select-multiple-dynamic/input.svelte

@@ -3,6 +3,14 @@
 	let multiple;
 </script>
 
+<!-- ok -->
+<select bind:this={value} {multiple}>
+	<option>1</option>
+	<option>2</option>
+	<option>3</option>
+</select>
+
+<!-- error -->
 <select bind:value {multiple}>
 	<option>1</option>
 	<option>2</option>