MC-5602: CAPTCHA doesn't appear in login popup after refreshing page.

Author: omiroshnichenko

app/code/Magento/Captcha/CustomerData/Captcha.php

@@ -11,7 +11,7 @@
 use Magento\Customer\CustomerData\SectionSourceInterface;
 
 /**
- * Cart source
+ * Captcha section
  */
 class Captcha extends \Magento\Framework\DataObject implements SectionSourceInterface
 {

app/code/Magento/Captcha/Model/DefaultModel.php

@@ -486,7 +486,7 @@ private function getTargetForms()
     /**
      * Get captcha word
      *
-     * @return string
+     * @return string|null
      */
     public function getWord()
     {
@@ -497,7 +497,7 @@ public function getWord()
     /**
      * Get captcha words
      *
-     * @return string
+     * @return string|null
      */
     private function getWords()
     {

app/code/Magento/Captcha/Test/Mftf/Test/CaptchaFormsDisplayingTest.xml

@@ -84,17 +84,18 @@
             </createData>
         </before>
         <after>
-            <deleteData createDataKey="createCategory" stepKey="deleteCategory"/>
-            <deleteData createDataKey="createSimpleProduct" stepKey="deleteSimpleProduct1"/>
             <magentoCLI command="config:set checkout/options/guest_checkout 1" stepKey="enableGuestCheckout"/>
             <magentoCLI command="config:set customer/captcha/failed_attempts_login 3" stepKey="increaseLoginAttempt"/>
+            <deleteData createDataKey="createCategory" stepKey="deleteCategory"/>
+            <deleteData createDataKey="createSimpleProduct" stepKey="deleteSimpleProduct1"/>
         </after>
         <amOnPage url="{{StorefrontProductPage.url($$createSimpleProduct.sku$$)}}" stepKey="openProductPage"/>
         <waitForPageLoad stepKey="waitForPageLoad"/>
         <click selector="{{StorefrontProductActionSection.addToCart}}" stepKey="addToCart" />
         <waitForText userInput="You added $$createSimpleProduct.name$$ to your shopping cart." stepKey="waitForText"/>
         <click selector="{{StorefrontMinicartSection.showCart}}" stepKey="clickCart"/>
         <click selector="{{StorefrontMinicartSection.goToCheckout}}" stepKey="goToCheckout"/>
+        <waitForElementVisible selector="{{StorefrontCustomerSignInPopupFormSection.email}}" stepKey="waitEmailFieldVisible"/>
         <fillField selector="{{StorefrontCustomerSignInPopupFormSection.email}}" userInput="{{Simple_US_Customer.email}}" stepKey="fillCustomerEmail"/>
         <fillField selector="{{StorefrontCustomerSignInPopupFormSection.password}}" userInput="incorrectPassword" stepKey="fillIncorrectCustomerPassword"/>
         <click selector="{{StorefrontCustomerSignInPopupFormSection.signIn}}" stepKey="clickSignIn"/>