From 20252c6483ae8a0c404250dbe8b07713002fae57 Mon Sep 17 00:00:00 2001
From: "Alex Lam S.L" <alexlamsl@gmail.com>
Date: Sun, 17 Apr 2022 23:38:08 +0100
Subject: [PATCH] fix corner case in `merge_vars` (#5421)

fixes #5420
---
 lib/compress.js             |  3 ---
 test/compress/merge_vars.js | 30 ++++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/lib/compress.js b/lib/compress.js
index 1462cf5f..e3dec09a 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -6246,9 +6246,7 @@ Compressor.prototype.compress = function(node) {
             if (node instanceof AST_Try) {
                 var save_try = in_try;
                 in_try = node;
-                var save = segment;
                 walk_body(node, tw);
-                segment = save;
                 if (node.bcatch) {
                     if (node.bcatch.argname) node.bcatch.argname.mark_symbol(function(node) {
                         if (node instanceof AST_SymbolCatch) {
@@ -6266,7 +6264,6 @@ Compressor.prototype.compress = function(node) {
                     }
                 }
                 in_try = save_try;
-                segment = save;
                 if (node.bfinally) node.bfinally.walk(tw);
                 return true;
             }
diff --git a/test/compress/merge_vars.js b/test/compress/merge_vars.js
index 8d69731b..67635436 100644
--- a/test/compress/merge_vars.js
+++ b/test/compress/merge_vars.js
@@ -3702,3 +3702,33 @@ issue_5182: {
     ]
     node_version: ">=4"
 }
+
+issue_5420: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        do {
+            var a = "FAIL 1";
+            a && a.p;
+            a = "FAIL 2";
+            try {
+                continue;
+            } catch (e) {}
+            var b = "FAIL 3";
+        } while (console.log(b || "PASS"));
+    }
+    expect: {
+        do {
+            var a = "FAIL 1";
+            a && a.p;
+            a = "FAIL 2";
+            try {
+                continue;
+            } catch (e) {}
+            var b = "FAIL 3";
+        } while (console.log(b || "PASS"));
+    }
+    expect_stdout: "PASS"
+}