From 0bf519933d24669fea6402523e2a1b881ab8be97 Mon Sep 17 00:00:00 2001
From: Lukas Taegert-Atkinson <lukastaegert@users.noreply.github.com>
Date: Thu, 30 Nov 2023 06:10:08 +0100
Subject: [PATCH] Allow to redeclare parameters multiple times in nested scopes
 (#5276)

---
 src/ast/scopes/BlockScope.ts                  |  5 ++++-
 .../redeclare-var-parameter-nested/_config.js |  3 +++
 .../redeclare-var-parameter-nested/main.js    | 21 +++++++++++++++++++
 3 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 test/function/samples/ast-validations/redeclare-var-parameter-nested/_config.js
 create mode 100644 test/function/samples/ast-validations/redeclare-var-parameter-nested/main.js

diff --git a/src/ast/scopes/BlockScope.ts b/src/ast/scopes/BlockScope.ts
index c4146818f..ae5701482 100644
--- a/src/ast/scopes/BlockScope.ts
+++ b/src/ast/scopes/BlockScope.ts
@@ -22,7 +22,10 @@ export default class BlockScope extends ChildScope {
 			const existingVariable =
 				this.hoistedVariables?.get(name) || (this.variables.get(name) as LocalVariable | undefined);
 			if (existingVariable) {
-				if (existingVariable.kind === VariableKind.var) {
+				if (
+					existingVariable.kind === VariableKind.var ||
+					(kind === VariableKind.var && existingVariable.kind === VariableKind.parameter)
+				) {
 					existingVariable.addDeclaration(identifier, init);
 					return existingVariable;
 				}
diff --git a/test/function/samples/ast-validations/redeclare-var-parameter-nested/_config.js b/test/function/samples/ast-validations/redeclare-var-parameter-nested/_config.js
new file mode 100644
index 000000000..36a2b6a82
--- /dev/null
+++ b/test/function/samples/ast-validations/redeclare-var-parameter-nested/_config.js
@@ -0,0 +1,3 @@
+module.exports = defineTest({
+	description: 'allows to redeclare parameters with multiple nested vars'
+});
diff --git a/test/function/samples/ast-validations/redeclare-var-parameter-nested/main.js b/test/function/samples/ast-validations/redeclare-var-parameter-nested/main.js
new file mode 100644
index 000000000..4973c455d
--- /dev/null
+++ b/test/function/samples/ast-validations/redeclare-var-parameter-nested/main.js
@@ -0,0 +1,21 @@
+export function f(val) {
+	{
+		var val = 1;
+		var val = 2;
+	}
+	assert.equal(val, 2);
+}
+f(0);
+
+export function g(val) {
+	{
+		{
+			var val = 1;
+		}
+		{
+			var val = 2;
+		}
+	}
+	assert.equal(val, 2);
+}
+g(0);