Fixes stack overflow on instance.save() with a reversed hasOne associ…

…ation (#338)

lib/Instance.js

@@ -12,6 +12,7 @@ function Instance(Model, opts) {
 	opts.changes = (opts.is_new ? Object.keys(opts.data) : []);
 	opts.extrachanges = [];
 
+	var instance_saving = false;
 	var events = {};
 	var instance = {};
 	var emitEvent = function () {
@@ -86,13 +87,26 @@ function Instance(Model, opts) {
 		});
 	};
 	var saveError = function (cb, err) {
+		instance_saving = false;
+
 		emitEvent("save", err, instance);
+
 		Hook.trigger(instance, opts.hooks.afterSave, false);
+
 		if (typeof cb === "function") {
 			cb(err, instance);
 		}
 	};
 	var saveInstance = function (cb, saveOptions) {
+		// what this condition means:
+		// - If the instance is in state mode
+		// - AND it's not an association that is asking it to save
+		//   -> return has already saved
+		if (instance_saving && !(saveOptions.saveAssociations === false)) {
+			return cb(null, instance);
+		}
+		instance_saving = true;
+
 		handleValidations(function (err) {
 			if (err) {
 				return saveError(cb, err);
@@ -127,6 +141,8 @@ function Instance(Model, opts) {
 		});
 	};
 	var afterSave = function (cb, create, err) {
+		instance_saving = false;
+
 		emitEvent("save", err, instance);
 
 		if (create) {
@@ -498,9 +514,10 @@ function Instance(Model, opts) {
 
 			while (arguments.length > 0) {
 				arg = Array.prototype.shift.call(arguments);
-				switch(typeof arg) {
+
+				switch (typeof arg) {
 					case 'object':
-						switch(objCount) {
+						switch (objCount) {
 							case 0:
 								data = arg;
 								break;

test/integration/instance.js

@@ -50,6 +50,52 @@ describe("Model instance", function() {
 		return db.close();
 	});
 
+	describe("#save", function () {
+		var main_item, item;
+
+		before(function (done) {
+			main_item = db.define("main_item", {
+				name      : String
+			}, {
+				auteFetch : true
+			});
+			item = db.define("item", {
+				name      : String
+			}, {
+				cache     : false
+			});
+			item.hasOne("main_item", main_item, {
+				reverse   : "items",
+				autoFetch : true
+			});
+
+			return helper.dropSync([ main_item, item ], function () {
+				main_item.create({
+					name : "Main Item"
+				}, function (err, mainItem) {
+					item.create({
+						name : "Item"
+					}, function (err, Item) {
+						mainItem.setItems(Item, function (err) {
+							should.not.exist(err);
+
+							return done();
+						});
+					});
+				});
+			});
+		});
+
+		it("should have a saving state to avoid loops", function (done) {
+			main_item.find({ name : "Main Item" }).first(function (err, mainItem) {
+				mainItem.save({ name : "new name" }, function (err) {
+					should.not.exist(err);
+					return done();
+				});
+			});
+		});
+	});
+
 	describe("#isInstance", function () {
 		it("should always return true for instances", function (done) {
 			should.equal((new Person).isInstance, true);