From 212ce4608ec24ba36868818b1ca662517b6ecb64 Mon Sep 17 00:00:00 2001
From: "Alex Lam S.L" <alexlamsl@gmail.com>
Date: Sun, 20 Feb 2022 13:38:04 +0000
Subject: [PATCH] fix corner case in `evaluate` (#5363)

fixes #5362
---
 lib/compress.js           |  7 +++++--
 test/compress/evaluate.js | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/lib/compress.js b/lib/compress.js
index dd0edd5a63..6b083d082f 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -10799,8 +10799,11 @@ Compressor.prototype.compress = function(node) {
         }
         switch (op) {
           case "+":
-            if (compressor.option("evaluate") && exp.is_number(compressor, true)) return exp;
-            break;
+            if (!compressor.option("evaluate")) break;
+            if (!exp.is_number(compressor, true)) break;
+            var parent = compressor.parent();
+            if (parent instanceof AST_UnaryPrefix && parent.operator == "delete") break;
+            return exp;
           case "-":
             if (exp instanceof AST_Infinity) exp = exp.transform(compressor);
             // avoids infinite recursion of numerals
diff --git a/test/compress/evaluate.js b/test/compress/evaluate.js
index 18527fb09e..da45378429 100644
--- a/test/compress/evaluate.js
+++ b/test/compress/evaluate.js
@@ -3294,3 +3294,39 @@ issue_5356: {
     }
     expect_stdout: "NaN"
 }
+
+issue_5362_1: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = -console;
+        console.log(delete +a);
+    }
+    expect: {
+        var a = -console;
+        console.log((+a, true));
+    }
+    expect_stdout: "true"
+}
+
+issue_5362_2: {
+    options = {
+        evaluate: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unsafe: true,
+        unused: true,
+    }
+    input: {
+        var a = -console;
+        console.log(delete +a);
+    }
+    expect: {
+        console.log(true);
+    }
+    expect_stdout: "true"
+}