From fb035617996c416fd68d571fe351848d0e5aa506 Mon Sep 17 00:00:00 2001
From: "Alex Lam S.L" <alexlamsl@gmail.com>
Date: Sun, 2 May 2021 00:28:31 +0100
Subject: [PATCH] fix corner case in `hoist_vars` (#4894)

fixes #4893
---
 lib/compress.js             |  3 +-
 test/compress/hoist_vars.js | 78 +++++++++++++++++++++++++++++++++++++
 test/compress/pure_funcs.js | 12 +++---
 test/compress/templates.js  |  2 +-
 4 files changed, 87 insertions(+), 8 deletions(-)

diff --git a/lib/compress.js b/lib/compress.js
index 39392c9737..b02a116357 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -1793,7 +1793,7 @@ merge(Compressor.prototype, {
                         return make_node(AST_Assign, candidate, {
                             operator: "=",
                             left: make_node(AST_SymbolRef, candidate.name, candidate.name),
-                            right: candidate.value
+                            right: candidate.value,
                         });
                     }
                     var assign = candidate;
@@ -8433,6 +8433,7 @@ merge(Compressor.prototype, {
             if (value) {
                 if (value instanceof AST_Sequence) value = value.clone();
                 var name = make_node(AST_SymbolRef, defn.name, defn.name);
+                name.fixed = value;
                 a.push(make_node(AST_Assign, defn, {
                     operator: "=",
                     left: name,
diff --git a/test/compress/hoist_vars.js b/test/compress/hoist_vars.js
index 4ca2ce5b5b..e3972b8a6b 100644
--- a/test/compress/hoist_vars.js
+++ b/test/compress/hoist_vars.js
@@ -295,3 +295,81 @@ issue_4859: {
     }
     expect_stdout: "Infinity"
 }
+
+issue_4893_1: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        hoist_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {}
+            var a = null;
+            var b = null;
+            var c = null;
+            b.p += a = 42;
+            f;
+        }
+        try {
+            f();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try{
+            (function f() {
+                var b;
+                b = null;
+                b.p += 42;
+                f;
+            })();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4893_2: {
+    options = {
+        collapse_vars: true,
+        hoist_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function g() {}
+            var a = null;
+            var b = null;
+            var c = null;
+            b.p += a = 42;
+            f;
+        }
+        try {
+            f();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        try{
+            (function() {
+                var b;
+                b = null;
+                b.p += 42;
+            })();
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}
diff --git a/test/compress/pure_funcs.js b/test/compress/pure_funcs.js
index 98768423f2..bf38003c13 100644
--- a/test/compress/pure_funcs.js
+++ b/test/compress/pure_funcs.js
@@ -133,7 +133,7 @@ conditional: {
 relational: {
     options = {
         pure_funcs: [ "foo" ],
-        side_effects :true,
+        side_effects: true,
     }
     input: {
         foo() in new foo();
@@ -158,7 +158,7 @@ relational: {
 arithmetic: {
     options = {
         pure_funcs: [ "foo" ],
-        side_effects :true,
+        side_effects: true,
     }
     input: {
         foo() + foo();
@@ -183,7 +183,7 @@ arithmetic: {
 boolean_and: {
     options = {
         pure_funcs: [ "foo" ],
-        side_effects :true,
+        side_effects: true,
     }
     input: {
         foo() && foo();
@@ -208,7 +208,7 @@ boolean_and: {
 boolean_or: {
     options = {
         pure_funcs: [ "foo" ],
-        side_effects :true,
+        side_effects: true,
     }
     input: {
         foo() || foo();
@@ -233,7 +233,7 @@ boolean_or: {
 assign: {
     options = {
         pure_funcs: [ "foo" ],
-        side_effects :true,
+        side_effects: true,
     }
     input: {
         var a;
@@ -256,7 +256,7 @@ assign: {
 unary: {
     options = {
         pure_funcs: [ "foo" ],
-        side_effects :true,
+        side_effects: true,
     }
     input: {
         typeof foo();
diff --git a/test/compress/templates.js b/test/compress/templates.js
index a27c6b8b4d..e46f3c0616 100644
--- a/test/compress/templates.js
+++ b/test/compress/templates.js
@@ -343,7 +343,7 @@ issue_4676: {
         reduce_vars: true,
         templates: true,
         toplevel: true,
-        unsafe:true,
+        unsafe: true,
         unused: true,
     }
     input: {