From cc7317deec506844dc95e96b529bd0c9d4618aac Mon Sep 17 00:00:00 2001
From: NickMitrokhin <nikolai.mitrokhin@devexpress.com>
Date: Wed, 6 May 2020 16:48:39 +0300
Subject: [PATCH 1/3] Fixes the issue

---
 js/ui/button.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/js/ui/button.js b/js/ui/button.js
index 3eb968053af0..416ec913429e 100644
--- a/js/ui/button.js
+++ b/js/ui/button.js
@@ -133,11 +133,11 @@ class Button extends Widget {
                         this.option('disabled', true);
 
                         complete.then(({ status }) => {
-                            needValidate = true;
                             this.option('disabled', false);
 
                             validationStatus = status;
                             validationStatus === 'valid' && this._submitInput().click();
+                            needValidate = true;
                         });
                     }
                 }

From 843ace6ff63283a860323218ce06f4afad05e206 Mon Sep 17 00:00:00 2001
From: NickMitrokhin <nikolai.mitrokhin@devexpress.com>
Date: Wed, 6 May 2020 16:49:06 +0300
Subject: [PATCH 2/3] Adds a test

---
 .../DevExpress.ui.widgets/button.tests.js     | 50 +++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/testing/tests/DevExpress.ui.widgets/button.tests.js b/testing/tests/DevExpress.ui.widgets/button.tests.js
index 6df9b7e79a9b..b36159e5ecdb 100644
--- a/testing/tests/DevExpress.ui.widgets/button.tests.js
+++ b/testing/tests/DevExpress.ui.widgets/button.tests.js
@@ -542,6 +542,56 @@ QUnit.module('submit behavior', {
         ValidationEngine.registerValidatorInGroup('testGroup', validator);
         this.$element.trigger('dxclick');
     });
+
+    QUnit.test('Form should be submitted only when an async validation rule is passed positively (T887207)', function(assert) {
+        this.clock.restore();
+        let value = 'a';
+        const validValue = 'b';
+        const validator = new Validator($('<div>').appendTo(this.$form), {
+            adapter: sinon.createStubInstance(DefaultAdapter),
+            validationRules: [{
+                type: 'async',
+                validationCallback: function() {
+                    const d = new Deferred();
+                    setTimeout(() => {
+                        d.resolve({
+                            isValid: value === validValue
+                        });
+                    }, 10);
+                    return d.promise();
+                }
+            }]
+        });
+        const done = assert.async();
+        const onSubmit = () => {
+            assert.strictEqual(value, validValue, 'submitted with valid value');
+
+            this.$form.off('submit', onSubmit);
+            done();
+        };
+        const triggerButtonClick = () => {
+            this.$element.trigger('dxclick');
+        };
+
+        this.$form.on('submit', onSubmit);
+
+        this.$element.dxButton({
+            validationGroup: 'testGroup',
+            onOptionChanged: function(args) {
+                if(args.name === 'disabled') {
+                    if(args.value === false && validator._validationInfo.result.status === 'invalid') {
+                        setTimeout(function() {
+                            value = validValue;
+                            triggerButtonClick();
+                        });
+                    }
+                }
+            }
+        });
+
+        ValidationEngine.registerValidatorInGroup('testGroup', validator);
+        triggerButtonClick();
+    });
 });
 
 QUnit.module('templates', () => {

From 2d399d6b74ce6a2ffc6d82abe057a062b20ba164 Mon Sep 17 00:00:00 2001
From: NickMitrokhin <nikolai.mitrokhin@devexpress.com>
Date: Wed, 6 May 2020 18:38:41 +0300
Subject: [PATCH 3/3] Test refactoring

(cherry picked from commit 83da0a98c26db0a46f66c9b24e93e0edb81da1ab)
---
 testing/tests/DevExpress.ui.widgets/button.tests.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/testing/tests/DevExpress.ui.widgets/button.tests.js b/testing/tests/DevExpress.ui.widgets/button.tests.js
index b36159e5ecdb..b5fd297ae46d 100644
--- a/testing/tests/DevExpress.ui.widgets/button.tests.js
+++ b/testing/tests/DevExpress.ui.widgets/button.tests.js
@@ -566,6 +566,7 @@ QUnit.module('submit behavior', {
         const onSubmit = () => {
             assert.strictEqual(value, validValue, 'submitted with valid value');
 
+            ValidationEngine.initGroups();
             this.$form.off('submit', onSubmit);
             done();
         };