ENGCOM-5174: issue fixed #8258 - assign indices for all array inputs so that validation works properly #15383

 - Merge Pull Request #15383 from jayankaghosh/magento2:issue-8258
 - Merged commits:
   1. 113440f
   2. 874d770
   3. 84355a3
   4. d5c41b6
   5. 156ac16
   6. 65a2c17
   7. 97c03f5
   8. 224f737
   9. 908100b
   10. 38b9709
   11. 388d31d
   12. ee288c1
   13. 11fb048
   14. 38cec68
   15. 2b231c5
   16. 2816a49

Author: magento-engcom-team

dev/tests/functional/tests/app/Magento/CheckoutAgreements/Test/Block/Adminhtml/Block/Agreement/Edit/AgreementsForm.xml

@@ -18,7 +18,7 @@
             <input>select</input>
         </mode>
         <stores>
-            <selector>[name="stores[]"]</selector>
+            <selector>[name="stores[0]"]</selector>
             <input>multiselectgrouplist</input>
         </stores>
         <checkbox_text />

dev/tests/functional/tests/app/Magento/Newsletter/Test/Block/Adminhtml/Queue/Edit/QueueForm.xml

@@ -11,7 +11,7 @@
             <selector>input[name='start_at']</selector>
         </queue_start_at>
         <stores>
-            <selector>select[name="stores[]"]</selector>
+            <selector>select[name="stores[0]"]</selector>
             <input>multiselectgrouplist</input>
         </stores>
         <newsletter_subject>

dev/tests/functional/tests/app/Magento/Reports/Test/Block/Adminhtml/Sales/Coupons/Filter.xml

@@ -29,7 +29,7 @@
             <input>select</input>
         </price_rule_type>
         <order_statuses>
-            <selector>[name="order_statuses[]"]</selector>
+            <selector>[name="order_statuses[0]"]</selector>
             <input>multiselect</input>
         </order_statuses>
         <rules_list>

dev/tests/functional/tests/app/Magento/Reports/Test/Block/Adminhtml/Sales/TaxRule/Filter.xml

@@ -23,7 +23,7 @@
             <input>select</input>
         </show_order_statuses>
         <order_statuses>
-            <selector>[name="order_statuses[]"]</selector>
+            <selector>[name="order_statuses[0]"]</selector>
             <input>multiselect</input>
         </order_statuses>
         <show_empty_rows>

dev/tests/functional/tests/app/Magento/Review/Test/Block/Adminhtml/Rating/Edit/RatingForm.xml

@@ -12,7 +12,7 @@
         <strategy>css selector</strategy>
         <fields>
             <stores>
-                <selector>[name="stores[]"]</selector>
+                <selector>[name="stores[0]"]</selector>
                 <input>multiselectgrouplist</input>
             </stores>
             <is_active>

dev/tests/functional/tests/app/Magento/Sales/Test/Block/Adminhtml/Report/Filter/Form.xml

@@ -26,7 +26,7 @@
             <input>select</input>
         </show_order_statuses>
         <order_statuses>
-            <selector>[name="order_statuses[]"]</selector>
+            <selector>[name="order_statuses[0]"]</selector>
             <input>multiselect</input>
         </order_statuses>
         <show_actual_columns>

dev/tests/functional/tests/app/Magento/Widget/Test/Block/Adminhtml/Widget/Instance/Edit/Tab/ParametersType/RecentlyComparedProducts.xml

@@ -12,13 +12,13 @@
         </page_size>
         <show_attributes>
             <selector>
-                .control [name="parameters[show_attributes][]"]
+                .control [name="parameters[show_attributes][1]"]
             </selector>
             <input>multiselect</input>
         </show_attributes>
         <show_buttons>
             <selector>
-                .control [name="parameters[show_buttons][]"]
+                .control [name="parameters[show_buttons][2]"]
             </selector>
             <input>multiselect</input>
         </show_buttons>

dev/tests/functional/tests/app/Magento/Widget/Test/Block/Adminhtml/Widget/Instance/Edit/Tab/ParametersType/RecentlyViewedProducts.xml

@@ -12,13 +12,13 @@
         </page_size>
         <show_attributes>
             <selector>
-                .control [name="parameters[show_attributes][]"]
+                .control [name="parameters[show_attributes][1]"]
             </selector>
             <input>multiselect</input>
         </show_attributes>
         <show_buttons>
             <selector>
-                .control [name="parameters[show_buttons][]"]
+                .control [name="parameters[show_buttons][2]"]
             </selector>
             <input>multiselect</input>
         </show_buttons>

dev/tests/functional/tests/app/Magento/Widget/Test/Block/Adminhtml/WidgetForm.xml

@@ -32,13 +32,13 @@
         <page_size />
         <show_attributes>
             <selector>
-                .control [name="parameters[show_attributes][]"]
+                .control [name="parameters[show_attributes][1]"]
             </selector>
             <input>multiselect</input>
         </show_attributes>
         <show_buttons>
             <selector>
-                .control [name="parameters[show_buttons][]"]
+                .control [name="parameters[show_buttons][2]"]
             </selector>
             <input>multiselect</input>
         </show_buttons>

lib/web/mage/validation.js

@@ -1949,13 +1949,14 @@
                  *  Before submitting the actual form, remove the previously assigned indices
                  *  @param {Object} form
                  */
-                this.options.submitHandler = function (form, event) {
+                this.options.submitHandler = function (form) {
                     originalElements.forEach(function (element) {
                         element.element.attr('name', element.name);
                         element.element.removeAttr('orig-name');
                     });
 
-                    console.error(this.submit)
+                    console.error(this.submit);
+
                     /* Call the originalSubmitHandler if it's a function */
                     typeof originalSubmitHandler === 'function' ? originalSubmitHandler(form) : form.submit();
                 };
@@ -1964,6 +1965,7 @@
 
         /**
          * Validation listening.
+         *
          * @protected
          */
         _listenFormValidate: function () {