From 4382bfe848f36165459b59ddcb605976c0055187 Mon Sep 17 00:00:00 2001
From: "Alex Lam S.L" <alexlamsl@gmail.com>
Date: Mon, 13 Jun 2022 00:55:15 +0100
Subject: [PATCH] fix corner case in `collapse_vars` (#5513)

fixes #5512
---
 lib/compress.js          | 27 ++++++++++++++++-----------
 test/compress/classes.js | 30 ++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 11 deletions(-)

diff --git a/lib/compress.js b/lib/compress.js
index 2494d1d55f9..59f579f007a 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -2351,20 +2351,25 @@ Compressor.prototype.compress = function(node) {
                 // Scan computed keys, static fields & initializers in class
                 if (node instanceof AST_Class) {
                     if (node.name) node.name = node.name.transform(tt);
-                    if (node.extends) node.extends = node.extends.transform(tt);
-                    node.properties.reduce(function(props, prop) {
+                    if (!abort && node.extends) node.extends = node.extends.transform(tt);
+                    var fields = [], stats = [];
+                    for (var i = 0; !abort && i < node.properties.length; i++) {
+                        var prop = node.properties[i];
                         if (prop.key instanceof AST_Node) prop.key = prop.key.transform(tt);
-                        if (prop.static) {
-                            if (prop instanceof AST_ClassField) {
-                                if (prop.value) props.push(prop);
-                            } else if (prop instanceof AST_ClassInit) {
-                                props.unshift(prop);
-                            }
+                        if (!prop.static) continue;
+                        if (prop instanceof AST_ClassField) {
+                            if (prop.value) fields.push(prop);
+                        } else if (prop instanceof AST_ClassInit) {
+                            [].push.apply(stats, prop.value.body);
                         }
-                        return props;
-                    }, []).forEach(function(prop) {
+                    }
+                    for (var i = 0; !abort && i < stats.length; i++) {
+                        stats[i].transform(tt);
+                    }
+                    for (var i = 0; !abort && i < fields.length; i++) {
+                        var prop = fields[i];
                         prop.value = prop.value.transform(tt);
-                    });
+                    }
                     return node;
                 }
                 // Scan object only in a for-in/of statement
diff --git a/test/compress/classes.js b/test/compress/classes.js
index e0ce3e10872..2dc7e3b0f5d 100644
--- a/test/compress/classes.js
+++ b/test/compress/classes.js
@@ -3300,3 +3300,33 @@ issue_5504: {
     expect_stdout: "undefined"
     node_version: ">=12"
 }
+
+issue_5512: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        "use strict";
+        a = "PASS";
+        class A {
+            static {
+                console.log(a);
+            }
+            static p = "PASS";
+        }
+        var a;
+    }
+    expect: {
+        "use strict";
+        a = "PASS";
+        class A {
+            static {
+                console.log(a);
+            }
+            static p = "PASS";
+        }
+        var a;
+    }
+    expect_stdout: "PASS"
+    node_version: ">=16"
+}