From 636d97e180eb16bbde831b40a4fff59971216ef4 Mon Sep 17 00:00:00 2001
From: Tobias Koppers <tobias.koppers@googlemail.com>
Date: Wed, 17 Sep 2014 23:23:45 +0200
Subject: [PATCH] show warning when using HMR incorrectly

fixed #480
---
 lib/HotModuleReplacementPlugin.js | 34 ++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/lib/HotModuleReplacementPlugin.js b/lib/HotModuleReplacementPlugin.js
index 228eef4f5..61f6b8d33 100644
--- a/lib/HotModuleReplacementPlugin.js
+++ b/lib/HotModuleReplacementPlugin.js
@@ -152,7 +152,7 @@ HotModuleReplacementPlugin.prototype.apply = function(compiler) {
 			return this.asString([
 				source + ",",
 				"hot: hotCreateModule(" + varModuleId + "),",
-				"parents: [hotCurrentParent],",
+				"parents: hotCurrentParents,",
 				"children: []"
 			]);
 		});
@@ -211,20 +211,30 @@ var hotInitCode = Template.getFunctionContent(function() {
 	var hotApplyOnUpdate = true;
 	var hotCurrentHash = $hash$;
 	var hotCurrentModuleData = {};
-	var hotCurrentParent = 0;
+	var hotCurrentParents = [];
 
 	function hotCreateRequire(moduleId) {
 		var me = installedModules[moduleId];
+		if(!me) return $require$;
 		var fn = function(request) {
-			if(installedModules[request] && installedModules[request].parents.indexOf(moduleId) < 0)
-				installedModules[request].parents.push(moduleId);
-			if(me && me.children.indexOf(request) < 0)
-				me.children.push(request);
-			hotCurrentParent = moduleId;
+			if(me.hot.active) {
+				if(installedModules[request]) {
+					if(installedModules[request].parents.indexOf(moduleId) < 0)
+						installedModules[request].parents.push(moduleId);
+					if(me.children.indexOf(request) < 0)
+						me.children.push(request);
+				} else hotCurrentParents = [moduleId];
+			} else {
+				console.warn("[HMR] unexpected require(" + request + ") from disposed module " + moduleId);
+				hotCurrentParents = [];
+			}
 			return $require$(request);
 		};
-		for(var name in $require$)
-			fn[name] = $require$[name];
+		for(var name in $require$) {
+			if(Object.prototype.hasOwnProperty.call($require$, name)) {
+				fn[name] = $require$[name];
+			}
+		}
 		fn.e = function(chunkId, callback) {
 			if(hotStatus === "ready")
 				hotSetStatus("prepare");
@@ -261,6 +271,7 @@ var hotInitCode = Template.getFunctionContent(function() {
 			_disposeHandlers: [],
 
 			// Module API
+			active: true,
 			accept: function(dep, callback) {
 				if(typeof dep === "undefined")
 					hot._selfAccepted = true;
@@ -528,6 +539,9 @@ var hotInitCode = Template.getFunctionContent(function() {
 			}
 			hotCurrentModuleData[moduleId] = data;
 
+			// disable module (this disables requires from this module)
+			module.hot.active = false;
+
 			// remove module from cache
 			delete installedModules[moduleId];
 
@@ -600,7 +614,7 @@ var hotInitCode = Template.getFunctionContent(function() {
 		for(var i = 0; i < outdatedSelfAcceptedModules.length; i++) {
 			var item = outdatedSelfAcceptedModules[i];
 			var moduleId = item.module;
-			hotCurrentParent = moduleId;
+			hotCurrentParents = [moduleId];
 			try {
 				$require$(moduleId);
 			} catch(err) {