MAGETWO-94052: CAPTCHA does not appear in "Log in" popup window

 - Added validation if response is undefined

Author: YevSent

app/code/Magento/Captcha/Model/Customer/Plugin/AjaxLogin.php

@@ -104,7 +104,7 @@ public function aroundExecute(
                     if (!$captchaModel->isCorrect($captchaString)) {
                         $this->sessionManager->setUsername($username);
                         $captchaModel->logAttempt($username);
-                        return $this->returnJsonError(__('Incorrect CAPTCHA'));
+                        return $this->returnJsonError(__('Incorrect CAPTCHA'), true);
                     }
                 }
 
@@ -118,11 +118,12 @@ public function aroundExecute(
      * Gets Json response.
      *
      * @param \Magento\Framework\Phrase $phrase
+     * @param bool $isCaptchaRequired
      * @return Json
      */
-    private function returnJsonError(\Magento\Framework\Phrase $phrase): Json
+    private function returnJsonError(\Magento\Framework\Phrase $phrase, bool $isCaptchaRequired = false): Json
     {
         $resultJson = $this->resultJsonFactory->create();
-        return $resultJson->setData(['errors' => true, 'message' => $phrase]);
+        return $resultJson->setData(['errors' => true, 'message' => $phrase, 'captcha' => $isCaptchaRequired]);
     }
 }

app/code/Magento/Captcha/Test/Unit/Model/Customer/Plugin/AjaxLoginTest.php

@@ -158,7 +158,7 @@ public function testAroundExecuteIncorrectCaptcha()
         $this->resultJsonMock
             ->expects($this->once())
             ->method('setData')
-            ->with(['errors' => true, 'message' => __('Incorrect CAPTCHA')])
+            ->with(['errors' => true, 'message' => __('Incorrect CAPTCHA'), 'captcha' => true])
             ->will($this->returnSelf());
 
         $closure = function () {

app/code/Magento/Captcha/view/frontend/web/js/view/checkout/loginCaptcha.js

@@ -4,11 +4,12 @@
  */
 
 define([
+        'underscore',
         'Magento_Captcha/js/view/checkout/defaultCaptcha',
         'Magento_Captcha/js/model/captchaList',
         'Magento_Customer/js/action/login'
     ],
-    function (defaultCaptcha, captchaList, loginAction) {
+    function (_, defaultCaptcha, captchaList, loginAction) {
         'use strict';
 
         return defaultCaptcha.extend({
@@ -25,11 +26,11 @@ define([
                     this.setCurrentCaptcha(currentCaptcha);
 
                     loginAction.registerLoginCallback(function (loginData, response) {
-                        if (!response.errors) {
+                        if (!loginData['captcha_form_id'] || loginData['captcha_form_id'] !== self.formId) {
                             return;
                         }
 
-                        if (!loginData['captcha_form_id'] || loginData['captcha_form_id'] !== self.formId) {
+                        if (_.isUndefined(response) || !response.errors) {
                             return;
                         }
 

app/code/Magento/Customer/view/frontend/web/js/view/authentication-popup.js

@@ -84,7 +84,6 @@ define([
             if (formElement.validation() &&
                 formElement.validation('isValid')
             ) {
-                this.isLoading(true);
                 loginAction(loginData);
             }