From 35c8097b6ae30834a0b25fd07fb2935bb8871801 Mon Sep 17 00:00:00 2001
From: Tobias Koppers <tobias.koppers@googlemail.com>
Date: Tue, 25 Jul 2017 12:53:18 +0200
Subject: [PATCH] Make sure it's a real module when choosing for
 ModuleConcatenation

fixes #5095
---
 lib/optimize/ModuleConcatenationPlugin.js     |  3 ++-
 .../scope-hoisting/dll-plugin/index.js        |  5 +++++
 .../dll-plugin/webpack.config.js              | 19 +++++++++++++++++++
 3 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 test/configCases/scope-hoisting/dll-plugin/index.js
 create mode 100644 test/configCases/scope-hoisting/dll-plugin/webpack.config.js

diff --git a/lib/optimize/ModuleConcatenationPlugin.js b/lib/optimize/ModuleConcatenationPlugin.js
index 174cdbaa89f..6ae7dc61492 100644
--- a/lib/optimize/ModuleConcatenationPlugin.js
+++ b/lib/optimize/ModuleConcatenationPlugin.js
@@ -7,6 +7,7 @@
 const HarmonyImportDependency = require("../dependencies/HarmonyImportDependency");
 const ConcatenatedModule = require("./ConcatenatedModule");
 const HarmonyExportImportedSpecifierDependency = require("../dependencies/HarmonyExportImportedSpecifierDependency");
+const HarmonyCompatibilityDependency = require("../dependencies/HarmonyCompatibilityDependency");
 
 class ModuleConcatenationPlugin {
 	constructor(options) {
@@ -39,7 +40,7 @@ class ModuleConcatenationPlugin {
 				const possibleInners = new Set();
 				for(const module of modules) {
 					// Only harmony modules are valid for optimization
-					if(!module.meta || !module.meta.harmonyModule) {
+					if(!module.meta || !module.meta.harmonyModule || !module.dependencies.some(d => d instanceof HarmonyCompatibilityDependency)) {
 						continue;
 					}
 
diff --git a/test/configCases/scope-hoisting/dll-plugin/index.js b/test/configCases/scope-hoisting/dll-plugin/index.js
new file mode 100644
index 00000000000..90b28ea4e68
--- /dev/null
+++ b/test/configCases/scope-hoisting/dll-plugin/index.js
@@ -0,0 +1,5 @@
+import value from "dll/module";
+
+it("should not scope hoist delegated modules", function() {
+	value.should.be.eql("ok");
+});
diff --git a/test/configCases/scope-hoisting/dll-plugin/webpack.config.js b/test/configCases/scope-hoisting/dll-plugin/webpack.config.js
new file mode 100644
index 00000000000..07ad2bf34a4
--- /dev/null
+++ b/test/configCases/scope-hoisting/dll-plugin/webpack.config.js
@@ -0,0 +1,19 @@
+var webpack = require("../../../../");
+module.exports = {
+	plugins: [
+		new webpack.DllReferencePlugin({
+			name: "function(id) { return {default: 'ok'}; }",
+			scope: "dll",
+			content: {
+				"./module": {
+					id: 1,
+					meta: {
+						harmonyModule: true
+					},
+					exports: ["default"]
+				}
+			}
+		}),
+		new webpack.optimize.ModuleConcatenationPlugin()
+	]
+};