Let textsecure devices throw on identity key change

Restore error format, accidentally removed in 43d6efcd

// FREEBIE

js/libtextsecure.js

@@ -38109,6 +38109,13 @@ axolotlInternal.RecipientRecord = function() {
     window.textsecure.storage.devices = {
         saveKeysToDeviceObject: function(deviceObject) {
             var number = textsecure.utils.unencodeNumber(deviceObject.encodedNumber)[0];
+            return textsecure.storage.axolotl.getIdentityKey(number).then(function(identityKey) {
+                if (identityKey !== undefined && deviceObject.identityKey !== undefined && getString(identityKey) != getString(deviceObject.identityKey)) {
+                    var error = new Error("Identity key changed");
+                    error.identityKey = deviceObject.identityKey;
+                    throw error;
+                }
+
                 return textsecure.storage.axolotl.putIdentityKey(number, deviceObject.identityKey).then(function() {
                     tempKeys[deviceObject.encodedNumber] = {
                         preKey:  deviceObject.preKey,
@@ -38119,6 +38126,7 @@ axolotlInternal.RecipientRecord = function() {
                         registrationId: deviceObject.registrationId
                     };
                 });
+            });
         },
 
         removeTempKeysFromDevice: function(encodedNumber) {

libtextsecure/storage/devices.js

@@ -28,6 +28,13 @@
     window.textsecure.storage.devices = {
         saveKeysToDeviceObject: function(deviceObject) {
             var number = textsecure.utils.unencodeNumber(deviceObject.encodedNumber)[0];
+            return textsecure.storage.axolotl.getIdentityKey(number).then(function(identityKey) {
+                if (identityKey !== undefined && deviceObject.identityKey !== undefined && getString(identityKey) != getString(deviceObject.identityKey)) {
+                    var error = new Error("Identity key changed");
+                    error.identityKey = deviceObject.identityKey;
+                    throw error;
+                }
+
                 return textsecure.storage.axolotl.putIdentityKey(number, deviceObject.identityKey).then(function() {
                     tempKeys[deviceObject.encodedNumber] = {
                         preKey:  deviceObject.preKey,
@@ -38,6 +45,7 @@
                         registrationId: deviceObject.registrationId
                     };
                 });
+            });
         },
 
         removeTempKeysFromDevice: function(encodedNumber) {