rewrite module reference correctly after replacing ConcatenatedModule

sokra · sokra · commit 6390240e05ec · 2018-05-30T09:51:11.000+02:00
fixes webpack#7443
diff --git a/lib/optimize/ModuleConcatenationPlugin.js b/lib/optimize/ModuleConcatenationPlugin.js
@@ -286,7 +286,13 @@ class ModuleConcatenationPlugin {
 							}
 							compilation.modules.push(newModule);
 							for (const reason of newModule.reasons) {
-								reason.dependency.module = newModule;
+								if (reason.dependency.module === concatConfiguration.rootModule)
+									reason.dependency.module = newModule;
+								if (
+									reason.dependency.redirectedModule ===
+									concatConfiguration.rootModule
+								)
+									reason.dependency.redirectedModule = newModule;
 							}
 							// TODO: remove when LTS node version contains fixed v8 version
 							// @see https://github.com/webpack/webpack/pull/6613
diff --git a/test/cases/optimize/side-effects-scope-hoisting/index.js b/test/cases/optimize/side-effects-scope-hoisting/index.js
@@ -0,0 +1,8 @@
+import { a } from "pmodule";
+
+it("should not crash with null id", function() {
+	expect(a).toBe("a");
+});
+
+if(Math === undefined)
+	console.log(module); // prevent scope hoisting of this module
