MAGETWO-83742: [Backport 2.1-develop] #10767 Race condition causing duplicate orders with double-clicks on Braintree "Pay" button #11901

Author: Oleksii Korshenko

app/code/Magento/Braintree/view/frontend/web/js/view/payment/method-renderer/hosted-fields.js

@@ -61,7 +61,7 @@ define([
         },
 
         /**
-         * @returns {Bool}
+         * @returns {Boolean}
          */
         isVaultEnabled: function () {
             return this.vaultEnabler.isVaultEnabled();
@@ -144,10 +144,19 @@ define([
         },
 
         /**
-         * Trigger order placing
+         * Returns state of place order button
+         * @returns {Boolean}
+         */
+        isButtonActive: function () {
+            return this.isActive() && this.isPlaceOrderActionAllowed();
+        },
+
+        /**
+         * Triggers order placing
          */
         placeOrderClick: function () {
             if (this.validateCardType()) {
+                this.isPlaceOrderActionAllowed(false);
                 $(this.getSelector('submit')).trigger('click');
             }
         },

app/code/Magento/Braintree/view/frontend/web/template/payment/form.html

@@ -139,10 +139,9 @@
                 <button class="action primary checkout"
                         type="submit"
                         data-bind="
-                        click: placeOrderClick,
-                        attr: {title: $t('Place Order')},
-                            css: {disabled: !isPlaceOrderActionAllowed()},
-                            enable: isActive()
+                            click: placeOrderClick,
+                            attr: {title: $t('Place Order')},
+                            enable: isButtonActive()
                         "
                         disabled>
                     <span data-bind="i18n: 'Place Order'"></span>