From 5b5f6e329cdaab4c8e89ad1d1c4c8f588d65e6a6 Mon Sep 17 00:00:00 2001
From: "Alex Lam S.L" <alexlamsl@gmail.com>
Date: Thu, 8 Sep 2022 03:49:40 +0100
Subject: [PATCH] fix corner case in `ie` (#5652)

fixes #5651
---
 lib/scope.js                    |  5 +++--
 test/compress/default-values.js | 25 +++++++++++++++++++++++++
 test/compress/destructured.js   | 25 +++++++++++++++++++++++++
 3 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/lib/scope.js b/lib/scope.js
index e3e4248d8e2..c2108c50f16 100644
--- a/lib/scope.js
+++ b/lib/scope.js
@@ -369,8 +369,9 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
     // pass 3: fix up any scoping issue with IE8
     if (options.ie) self.walk(new TreeWalker(function(node) {
         if (node instanceof AST_SymbolCatch) {
-            var scope = node.thedef.defun;
-            if (scope.name instanceof AST_SymbolLambda && scope.name.name == node.name) {
+            var def = node.thedef;
+            var scope = def.defun;
+            if (def.name != "arguments" && scope.name instanceof AST_SymbolLambda && scope.name.name == def.name) {
                 scope = scope.parent_scope.resolve();
             }
             redefine(node, scope);
diff --git a/test/compress/default-values.js b/test/compress/default-values.js
index ac2be8400d7..38f6552da13 100644
--- a/test/compress/default-values.js
+++ b/test/compress/default-values.js
@@ -3044,3 +3044,28 @@ issue_5566_5: {
     expect_stdout: "foo bar"
     node_version: ">=6"
 }
+
+issue_5651: {
+    options = {
+        ie: true,
+        unused: true,
+    }
+    input: {
+        console.log(function arguments(a = "FAIL") {
+            try {} catch (arguments) {
+                var arguments;
+            }
+            return arguments[0];
+        }());
+    }
+    expect: {
+        console.log(function arguments(a = "FAIL") {
+            try {} catch (arguments) {
+                var arguments;
+            }
+            return arguments[0];
+        }());
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}
diff --git a/test/compress/destructured.js b/test/compress/destructured.js
index 284130d7a53..f79570f35b0 100644
--- a/test/compress/destructured.js
+++ b/test/compress/destructured.js
@@ -3844,3 +3844,28 @@ issue_5573: {
     ]
     node_version: ">=6"
 }
+
+issue_5651: {
+    options = {
+        ie: true,
+        unused: true,
+    }
+    input: {
+        console.log(function arguments({}) {
+            try {} catch (arguments) {
+                var arguments;
+            }
+            return arguments[0];
+        }("PASS"));
+    }
+    expect: {
+        console.log(function arguments({}) {
+            try {} catch (arguments) {
+                var arguments;
+            }
+            return arguments[0];
+        }("PASS"));
+    }
+    expect_stdout: true
+    node_version: ">=6"
+}