1 files changed, 32 insertions, 0 deletions
diff --git a/test/compress/merge_vars.js b/test/compress/merge_vars.js
index 6ada9297..b61b486d 100644
--- a/test/compress/merge_vars.js
+++ b/test/compress/merge_vars.js
@@ -3092,3 +3092,35 @@ issue_4237_2: {
     }
     expect_stdout: "PASS"
 }
+
+issue_4253: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        switch (0) {
+          default:
+            var a = "FAIL";
+            a = a && a;
+            try {
+                break;
+            } catch (e) {}
+            var b = 42;
+        }
+        console.log(b);
+    }
+    expect: {
+        switch (0) {
+          default:
+            var a = "FAIL";
+            a = a && a;
+            try {
+                break;
+            } catch (e) {}
+            var b = 42;
+        }
+        console.log(b);
+    }
+    expect_stdout: "undefined"
+}