allow duplicates of the same action on an element (#5875)

src/compiler/parse/state/tag.ts

@@ -376,7 +376,7 @@ function read_attribute(parser: Parser, unique_names: Set<string>) {
 
 		if (type === 'Binding' && directive_name !== 'this') {
 			check_unique(directive_name);
-		} else if (type !== 'EventHandler') {
+		} else if (type !== 'EventHandler' && type !== 'Action') {
 			check_unique(name);
 		}
 

test/parser/samples/action-duplicate/input.svelte

@@ -0,0 +1 @@
+<input use:autofocus use:autofocus>

test/parser/samples/action-duplicate/output.json

@@ -0,0 +1,34 @@
+{
+	"html": {
+		"start": 0,
+		"end": 35,
+		"type": "Fragment",
+		"children": [
+			{
+				"start": 0,
+				"end": 35,
+				"type": "Element",
+				"name": "input",
+				"attributes": [
+					{
+						"start": 7,
+						"end": 20,
+						"type": "Action",
+						"name": "autofocus",
+						"modifiers": [],
+						"expression": null
+					},
+					{
+						"start": 21,
+						"end": 34,
+						"type": "Action",
+						"name": "autofocus",
+						"modifiers": [],
+						"expression": null
+					}
+				],
+				"children": []
+			}
+		]
+	}
+}