From 21fc8f4630bccdb8b0a33747c2de8fd377e83138 Mon Sep 17 00:00:00 2001
From: "Alex Lam S.L" <alexlamsl@gmail.com>
Date: Tue, 15 Jun 2021 13:59:53 +0100
Subject: [PATCH] fix corner case in `switches` (#5011)

fixes #5010
---
 lib/compress.js           |  2 +-
 test/compress/switches.js | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/lib/compress.js b/lib/compress.js
index 44098d74..ed3b5a39 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -8506,7 +8506,7 @@ merge(Compressor.prototype, {
             }));
             return make_node(AST_BlockStatement, self, { body: decl }).optimize(compressor);
         }
-        if (exact_match ? !branch.expression.has_side_effects(compressor) : branch === default_branch) {
+        if (branch === default_branch || branch === exact_match && !branch.expression.has_side_effects(compressor)) {
             while (branch = body[body.length - 2]) {
                 if (branch instanceof AST_Default) break;
                 if (!has_declarations_only(branch)) break;
diff --git a/test/compress/switches.js b/test/compress/switches.js
index cbaa0644..af81b54c 100644
--- a/test/compress/switches.js
+++ b/test/compress/switches.js
@@ -1556,3 +1556,29 @@ issue_5008_4: {
     }
     expect_stdout: "PASS"
 }
+
+issue_5010: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        switches: true,
+    }
+    input: {
+        var a;
+        switch (42) {
+          case console.log("PASS"):
+          case a:
+            console.log("FAIL");
+          case 42:
+        }
+    }
+    expect: {
+        var a;
+        switch (42) {
+          case console.log("PASS"):
+          case a:
+            console.log("FAIL");
+        }
+    }
+    expect_stdout: "PASS"
+}