From f3a3925afb21b53b381c2f908b4a639ee019edc9 Mon Sep 17 00:00:00 2001
From: Joel Denning <joeldenning@gmail.com>
Date: Wed, 21 Nov 2018 18:55:27 -0700
Subject: [PATCH] Not depending on return value of super(). Fixes #9020.

---
 .../fixtures/arrow-functions/this/output.js   |  7 ++++--
 .../babel-traverse/src/path/conversion.js     |  8 +++++--
 .../babel-traverse/test/arrow-transform.js    | 24 +++++++++++++++----
 3 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/packages/babel-plugin-transform-arrow-functions/test/fixtures/arrow-functions/this/output.js b/packages/babel-plugin-transform-arrow-functions/test/fixtures/arrow-functions/this/output.js
index f13e5374e2bc..f85f02a77f4b 100644
--- a/packages/babel-plugin-transform-arrow-functions/test/fixtures/arrow-functions/this/output.js
+++ b/packages/babel-plugin-transform-arrow-functions/test/fixtures/arrow-functions/this/output.js
@@ -15,9 +15,12 @@ class Foo extends function () {} {
     };
 
     if (true) {
-      console.log(_this2 = super(), foo());
+      var _temp;
+
+      console.log((_temp = super(), _this2 = this, _temp), foo());
     } else {
-      _this2 = super();
+      super();
+      _this2 = this;
       console.log(foo());
     }
   }
diff --git a/packages/babel-traverse/src/path/conversion.js b/packages/babel-traverse/src/path/conversion.js
index cf45cc320b2b..b144f3b8ec0d 100644
--- a/packages/babel-traverse/src/path/conversion.js
+++ b/packages/babel-traverse/src/path/conversion.js
@@ -461,8 +461,12 @@ function getThisBinding(thisEnvFn, inConstructor) {
         if (supers.has(child.node)) return;
         supers.add(child.node);
 
-        child.replaceWith(
-          t.assignmentExpression("=", t.identifier(thisBinding), child.node),
+        child.insertAfter(
+          t.assignmentExpression(
+            "=",
+            t.identifier(thisBinding),
+            t.identifier("this"),
+          ),
         );
       },
     });
diff --git a/packages/babel-traverse/test/arrow-transform.js b/packages/babel-traverse/test/arrow-transform.js
index d74ca8f71196..6201de7134a2 100644
--- a/packages/babel-traverse/test/arrow-transform.js
+++ b/packages/babel-traverse/test/arrow-transform.js
@@ -82,7 +82,11 @@ describe("arrow function conversion", () => {
       () => this;
     `,
       `
-      var _supercall = (..._args) => _this = super(..._args),
+      var _supercall = (..._args) => {
+        var _temp;
+
+        return _temp = super(..._args), _this = this, _temp;
+      },
           _this;
 
       (function () {
@@ -115,9 +119,14 @@ describe("arrow function conversion", () => {
       (function () {
         _this;
       });
-      _this = super();
+      super();
+      _this = this;
       this;
-      () => _this = super();
+      () => {
+        var _temp;
+
+        return _temp = super(), _this = this, _temp;
+      }
       () => this;
     `,
       { methodName: "constructor", extend: true },
@@ -144,9 +153,14 @@ describe("arrow function conversion", () => {
 
         _this;
       }).bind(_arrowCheckId);
-      _this = super();
+      super();
+      _this = this;
       this;
-      () => _this = super();
+      () => {
+        var _temp;
+
+        return _temp = super(), _this = this, _temp;
+      }
       () => this;
     `,
       {