[8.x] Fixed BelongsToMany UpdateOrCreate Create operation

src/Illuminate/Database/Eloquent/Relations/BelongsToMany.php

@@ -634,7 +634,7 @@ public function firstOrCreate(array $attributes, array $joining = [], $touch = t
     public function updateOrCreate(array $attributes, array $values = [], array $joining = [], $touch = true)
     {
         if (is_null($instance = $this->where($attributes)->first())) {
-            return $this->create($values, $joining, $touch);
+            return $this->create(array_merge($attributes, $values), $joining, $touch);
         }
 
         $instance->fill($values);

tests/Database/DatabaseEloquentBelongsToManyTest.php

@@ -0,0 +1,138 @@
+<?php
+
+namespace Illuminate\Tests\Database;
+
+use Illuminate\Database\Capsule\Manager as DB;
+use Illuminate\Database\Eloquent\Model;
+use PHPUnit\Framework\TestCase;
+
+class DatabaseEloquentBelongsToManyTest extends TestCase
+{
+    protected function setUp(): void
+    {
+        $db = new DB;
+
+        $db->addConnection([
+            'driver' => 'sqlite',
+            'database' => ':memory:',
+        ]);
+
+        $db->bootEloquent();
+        $db->setAsGlobal();
+
+        $this->createSchema();
+    }
+
+    /**
+     * Setup the database schema.
+     *
+     * @return void
+     */
+    public function createSchema()
+    {
+        $this->schema()->create('users', function ($table) {
+            $table->id('id');
+        });
+
+        $this->schema()->create('articles', function ($table) {
+            $table->id('id');
+
+            $table->string('title');
+            $table->string('description');
+        });
+
+        $this->schema()->create('article_user', function ($table) {
+            $table->foreignId('article_id')->references('id')->on('articles');
+            $table->foreignId('user_id')->references('id')->on('users');
+        });
+    }
+
+    /**
+     * Tear down the database schema.
+     *
+     * @return void
+     */
+    protected function tearDown(): void
+    {
+        $this->schema()->drop('users');
+        $this->schema()->drop('articles');
+        $this->schema()->drop('article_user');
+    }
+
+    public function testCreateWithDesiredAttributesUsingUpdateOrCreate()
+    {
+        /** @var FakeUpdateOrCreateUser $user */
+        $user = FakeUpdateOrCreateUser::create();
+
+        $user->articles()->updateOrCreate(
+            ['title' => 'Fixing UpdateOrCreate'],
+            ['description' => 'Fixed']
+        );
+
+        $article = $user->articles()->first();
+
+        $this->assertSame($article->description, 'Fixed');
+    }
+
+    public function testUpdateWithDesiredAttributesUsingUpdateOrCreate()
+    {
+        /** @var FakeUpdateOrCreateUser $user */
+        $user = FakeUpdateOrCreateUser::create();
+        $user->articles()->create([
+            'title' => $title = 'Fixing UpdateOrCreate',
+            'description' => 'Not fixed',
+        ]);
+
+        $user->articles()->updateOrCreate(
+            ['title' => $title],
+            ['description' => 'Fixed']
+        );
+
+        $article = $user->articles()->first();
+
+        $this->assertSame($article->description, 'Fixed');
+    }
+
+    /**
+     * Get a database connection instance.
+     *
+     * @return \Illuminate\Database\ConnectionInterface
+     */
+    protected function connection()
+    {
+        return Model::getConnectionResolver()->connection();
+    }
+
+    /**
+     * Get a schema builder instance.
+     *
+     * @return \Illuminate\Database\Schema\Builder
+     */
+    protected function schema()
+    {
+        return $this->connection()->getSchemaBuilder();
+    }
+}
+
+class FakeUpdateOrCreateUser extends Model
+{
+    protected $table = 'users';
+
+    protected $fillable = ['email'];
+
+    public $timestamps = false;
+
+    public function articles()
+    {
+        return $this->belongsToMany(FakeUpdateOrCreateArticle::class, 'article_user', 'user_id', 'article_id');
+    }
+}
+
+class FakeUpdateOrCreateArticle extends Model
+{
+    protected $table = 'articles';
+
+    public $timestamps = false;
+
+    protected $fillable = ['title', 'description'];
+}