From a4a8ccea8c323f8a41a5f2e7df907f41876ff9f6 Mon Sep 17 00:00:00 2001
From: "Alex Lam S.L" <alexlamsl@gmail.com>
Date: Sun, 26 Apr 2020 20:31:19 +0100
Subject: [PATCH] fix corner case in `inline` (#3822)

fixes #3821
---
 lib/compress.js            |  8 +++++--
 test/compress/functions.js | 46 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/lib/compress.js b/lib/compress.js
index 3d1b17f3..67884a13 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -6130,8 +6130,12 @@ merge(Compressor.prototype, {
                     return;
                 }
                 if (node instanceof AST_Scope) return abort = true;
-                var def;
-                if (node instanceof AST_SymbolRef && fn.variables.get(node.name) === (def = node.definition())) {
+                if (node instanceof AST_SymbolRef) {
+                    var def = node.definition();
+                    if (fn.variables.get(node.name) !== def) {
+                        in_order = null;
+                        return;
+                    }
                     if (def.init instanceof AST_Defun) return abort = true;
                     if (is_lhs(node, this.parent())) return abort = true;
                     var index = resolve_index(def);
diff --git a/test/compress/functions.js b/test/compress/functions.js
index 4dc685be..b088ca87 100644
--- a/test/compress/functions.js
+++ b/test/compress/functions.js
@@ -4062,3 +4062,49 @@ issue_3777_2: {
     }
     expect_stdout: "PASS"
 }
+
+issue_3821_1: {
+    options = {
+        inline: true,
+    }
+    input: {
+        var a = 0;
+        console.log(function(b) {
+            return +a + b;
+        }(--a));
+    }
+    expect: {
+        var a = 0;
+        console.log(function(b) {
+            return +a + b;
+        }(--a));
+    }
+    expect_stdout: "-2"
+}
+
+issue_3821_2: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = "PASS";
+        function f(g, b) {
+            return g(), b;
+        }
+        console.log(f(function() {
+            a = "FAIL";
+        }, a));
+    }
+    expect: {
+        var a = "PASS";
+        function f(g, b) {
+            return g(), b;
+        }
+        console.log(f(function() {
+            a = "FAIL";
+        }, a));
+    }
+    expect_stdout: "PASS"
+}
-- 
2.34.1