From 42007e882ae66401ea09dcbc27cbafcc3cd3217f Mon Sep 17 00:00:00 2001
From: Tobias Koppers <tobias.koppers@googlemail.com>
Date: Tue, 22 Jan 2019 09:13:21 +0100
Subject: [PATCH] fixes #8666

---
 lib/optimize/ConcatenatedModule.js                         | 2 +-
 test/cases/scope-hoisting/esModule/index.js                | 6 ++++++
 test/cases/scope-hoisting/esModule/module.js               | 3 +++
 test/cases/scope-hoisting/esModule/other.js                | 1 +
 test/configCases/scope-hoisting/esModule/index.js          | 6 ++++++
 test/configCases/scope-hoisting/esModule/module.js         | 3 +++
 test/configCases/scope-hoisting/esModule/other.js          | 1 +
 test/configCases/scope-hoisting/esModule/webpack.config.js | 7 +++++++
 8 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 test/cases/scope-hoisting/esModule/index.js
 create mode 100644 test/cases/scope-hoisting/esModule/module.js
 create mode 100644 test/cases/scope-hoisting/esModule/other.js
 create mode 100644 test/configCases/scope-hoisting/esModule/index.js
 create mode 100644 test/configCases/scope-hoisting/esModule/module.js
 create mode 100644 test/configCases/scope-hoisting/esModule/other.js
 create mode 100644 test/configCases/scope-hoisting/esModule/webpack.config.js

diff --git a/lib/optimize/ConcatenatedModule.js b/lib/optimize/ConcatenatedModule.js
index aa244a2f550..f5ae70cd872 100644
--- a/lib/optimize/ConcatenatedModule.js
+++ b/lib/optimize/ConcatenatedModule.js
@@ -1096,7 +1096,7 @@ class ConcatenatedModule extends Module {
 
 		// add harmony compatibility flag (must be first because of possible circular dependencies)
 		const usedExports = this.rootModule.usedExports;
-		if (usedExports === true) {
+		if (usedExports === true || usedExports === null) {
 			result.add(
 				runtimeTemplate.defineEsModuleFlagStatement({
 					exportsArgument: this.exportsArgument
diff --git a/test/cases/scope-hoisting/esModule/index.js b/test/cases/scope-hoisting/esModule/index.js
new file mode 100644
index 00000000000..769d4eeba44
--- /dev/null
+++ b/test/cases/scope-hoisting/esModule/index.js
@@ -0,0 +1,6 @@
+it("should have the __esModule flag", () => {
+	return import("./module").then(mod => {
+		expect(mod.__esModule).toBe(true);
+		expect(mod.default).toBe(84);
+	})
+})
diff --git a/test/cases/scope-hoisting/esModule/module.js b/test/cases/scope-hoisting/esModule/module.js
new file mode 100644
index 00000000000..a6fa9eb3dd6
--- /dev/null
+++ b/test/cases/scope-hoisting/esModule/module.js
@@ -0,0 +1,3 @@
+import other from "./other";
+
+export default other * 2;
diff --git a/test/cases/scope-hoisting/esModule/other.js b/test/cases/scope-hoisting/esModule/other.js
new file mode 100644
index 00000000000..7a4e8a723a4
--- /dev/null
+++ b/test/cases/scope-hoisting/esModule/other.js
@@ -0,0 +1 @@
+export default 42;
diff --git a/test/configCases/scope-hoisting/esModule/index.js b/test/configCases/scope-hoisting/esModule/index.js
new file mode 100644
index 00000000000..769d4eeba44
--- /dev/null
+++ b/test/configCases/scope-hoisting/esModule/index.js
@@ -0,0 +1,6 @@
+it("should have the __esModule flag", () => {
+	return import("./module").then(mod => {
+		expect(mod.__esModule).toBe(true);
+		expect(mod.default).toBe(84);
+	})
+})
diff --git a/test/configCases/scope-hoisting/esModule/module.js b/test/configCases/scope-hoisting/esModule/module.js
new file mode 100644
index 00000000000..a6fa9eb3dd6
--- /dev/null
+++ b/test/configCases/scope-hoisting/esModule/module.js
@@ -0,0 +1,3 @@
+import other from "./other";
+
+export default other * 2;
diff --git a/test/configCases/scope-hoisting/esModule/other.js b/test/configCases/scope-hoisting/esModule/other.js
new file mode 100644
index 00000000000..7a4e8a723a4
--- /dev/null
+++ b/test/configCases/scope-hoisting/esModule/other.js
@@ -0,0 +1 @@
+export default 42;
diff --git a/test/configCases/scope-hoisting/esModule/webpack.config.js b/test/configCases/scope-hoisting/esModule/webpack.config.js
new file mode 100644
index 00000000000..b5fcc43ed62
--- /dev/null
+++ b/test/configCases/scope-hoisting/esModule/webpack.config.js
@@ -0,0 +1,7 @@
+module.exports = {
+	mode: "development",
+	devtool: false,
+	optimization: {
+		concatenateModules: true
+	}
+};