From 8ceb4b0492b1ba99cb43f77d3791ddb7a2131dc5 Mon Sep 17 00:00:00 2001
From: "Alex Lam S.L" <alexlamsl@gmail.com>
Date: Thu, 3 Feb 2022 05:13:35 +0000
Subject: [PATCH] fix corner case in `inline` (#5333)

fixes #5332
---
 lib/compress.js            | 25 +++++++++++++----
 test/compress/functions.js | 56 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+), 6 deletions(-)

diff --git a/lib/compress.js b/lib/compress.js
index 77d32768..1ea3b553 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -13049,17 +13049,30 @@ Compressor.prototype.compress = function(node) {
 
     function init_ref(compressor, name) {
         var sym = make_node(AST_SymbolRef, name, name);
-        var def = name.definition();
-        def.assignments++;
-        def.references.push(sym);
         var assign = make_node(AST_Assign, name, {
             operator: "=",
             left: sym,
             right: make_node(AST_Undefined, name).transform(compressor),
         });
-        sym.fixed = function() {
-            return assign.right;
-        };
+        var def = name.definition();
+        if (def.fixed) {
+            sym.fixed = function() {
+                return assign.right;
+            };
+            sym.fixed.assigns = [ assign ];
+            var visited = [];
+            def.references.forEach(function(ref) {
+                var fixed = ref.fixed;
+                if (!fixed || !push_uniq(visited, fixed)) return;
+                if (fixed.assigns) {
+                    fixed.assigns.unshift(assign);
+                } else {
+                    fixed.assigns = [ assign ];
+                }
+            });
+        }
+        def.assignments++;
+        def.references.push(sym);
         return assign;
     }
 
diff --git a/test/compress/functions.js b/test/compress/functions.js
index 7559755b..fa26d408 100644
--- a/test/compress/functions.js
+++ b/test/compress/functions.js
@@ -8151,3 +8151,59 @@ issue_5328: {
     }
     expect_stdout: ""
 }
+
+issue_5332_1: {
+    options = {
+        inline: true,
+        merge_vars: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        do {
+            var a = {};
+            for (A in a)
+                a;
+        } while (function() {
+            console.log(b);
+            var b = b;
+        }());
+    }
+    expect: {
+        do {
+            var a = {};
+            for (A in a);
+        } while (a = void 0, void console.log(a));
+    }
+    expect_stdout: "undefined"
+}
+
+issue_5332_2: {
+    options = {
+        inline: true,
+        merge_vars: true,
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        do {
+            var a = 42 in [];
+            for (A in a)
+                a;
+        } while (function() {
+            console.log(++b);
+            var b = b;
+        }());
+    }
+    expect: {
+        do {
+            var a = 42 in [];
+            for (A in a);
+        } while (a = void 0, void console.log(++a));
+    }
+    expect_stdout: "NaN"
+}