[10.x] Fix createOrFirst on transactions

src/Illuminate/Database/Eloquent/Builder.php

@@ -580,7 +580,7 @@ public function firstOrCreate(array $attributes = [], array $values = [])
     public function createOrFirst(array $attributes = [], array $values = [])
     {
         try {
-            return $this->create(array_merge($attributes, $values));
+            return $this->withSavepointIfNeeded(fn () => $this->create(array_merge($attributes, $values)));
         } catch (UniqueConstraintViolationException $exception) {
             return $this->where($attributes)->first();
         }
@@ -1709,6 +1709,21 @@ public function withCasts($casts)
         return $this;
     }
 
+    /**
+     * Execute the given Closure within a transaction savepoint if needed.
+     *
+     * @template TModelValue
+     *
+     * @param  \Closure(): TModelValue  $scope
+     * @return TModelValue
+     */
+    public function withSavepointIfNeeded(Closure $scope): mixed
+    {
+        return $this->getQuery()->getConnection()->transactionLevel() > 0
+            ? $this->getQuery()->getConnection()->transaction($scope)
+            : $scope();
+    }
+
     /**
      * Get the underlying query builder instance.
      *

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

@@ -643,14 +643,14 @@ public function firstOrCreate(array $attributes = [], array $values = [], array
     public function createOrFirst(array $attributes = [], array $values = [], array $joining = [], $touch = true)
     {
         try {
-            return $this->create(array_merge($attributes, $values), $joining, $touch);
+            return $this->getQuery()->withSavePointIfNeeded(fn () => $this->create(array_merge($attributes, $values), $joining, $touch));
         } catch (UniqueConstraintViolationException $exception) {
             // ...
         }
 
         try {
             return tap($this->related->where($attributes)->first(), function ($instance) use ($joining, $touch) {
-                $this->attach($instance, $joining, $touch);
+                $this->getQuery()->withSavepointIfNeeded(fn () => $this->attach($instance, $joining, $touch));
             });
         } catch (UniqueConstraintViolationException $exception) {
             return (clone $this)->where($attributes)->first();

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

@@ -252,7 +252,7 @@ public function firstOrCreate(array $attributes = [], array $values = [])
     public function createOrFirst(array $attributes = [], array $values = [])
     {
         try {
-            return $this->create(array_merge($attributes, $values));
+            return $this->getQuery()->withSavepointIfNeeded(fn () => $this->create(array_merge($attributes, $values)));
         } catch (UniqueConstraintViolationException $exception) {
             return $this->where($attributes)->first();
         }

tests/Database/DatabaseEloquentHasManyTest.php

@@ -181,6 +181,9 @@ public function testCreateOrFirstMethodWithValuesFindsFirstModel()
             );
         }));
 
+        $relation->getQuery()->shouldReceive('withSavepointIfNeeded')->once()->andReturnUsing(function ($scope) {
+            return $scope();
+        });
         $relation->getQuery()->shouldReceive('where')->once()->with(['foo' => 'bar'])->andReturn($relation->getQuery());
         $relation->getQuery()->shouldReceive('first')->once()->with()->andReturn($model = m::mock(stdClass::class));
 
@@ -192,6 +195,9 @@ public function testCreateOrFirstMethodCreatesNewModelWithForeignKeySet()
     {
         $relation = $this->getRelation();
 
+        $relation->getQuery()->shouldReceive('withSavepointIfNeeded')->once()->andReturnUsing(function ($scope) {
+            return $scope();
+        });
         $relation->getQuery()->shouldReceive('where')->never();
         $relation->getQuery()->shouldReceive('first')->never();
         $model = $this->expectCreatedModel($relation, ['foo']);
@@ -202,6 +208,9 @@ public function testCreateOrFirstMethodCreatesNewModelWithForeignKeySet()
     public function testCreateOrFirstMethodWithValuesCreatesNewModelWithForeignKeySet()
     {
         $relation = $this->getRelation();
+        $relation->getQuery()->shouldReceive('withSavepointIfNeeded')->once()->andReturnUsing(function ($scope) {
+            return $scope();
+        });
         $relation->getQuery()->shouldReceive('where')->never();
         $relation->getQuery()->shouldReceive('first')->never();
         $model = $this->expectCreatedModel($relation, ['foo' => 'bar', 'baz' => 'qux']);

tests/Database/DatabaseEloquentIntegrationTest.php

@@ -552,6 +552,22 @@ public function testCreateOrFirst()
         $this->assertSame('Nuno Maduro', $user4->name);
     }
 
+    public function testCreateOrFirstWithinTransaction()
+    {
+        $user1 = EloquentTestUniqueUser::create(['email' => '[email protected]']);
+
+        DB::transaction(function () use ($user1) {
+            $user2 = EloquentTestUniqueUser::createOrFirst(
+                ['email' => '[email protected]'],
+                ['name' => 'Taylor Otwell']
+            );
+
+            $this->assertEquals($user1->id, $user2->id);
+            $this->assertSame('[email protected]', $user2->email);
+            $this->assertNull($user2->name);
+        });
+    }
+
     public function testUpdateOrCreate()
     {
         $user1 = EloquentTestUser::create(['email' => '[email protected]']);

tests/Database/DatabaseEloquentMorphTest.php

@@ -227,6 +227,9 @@ public function testCreateOrFirstMethodFindsFirstModel()
             new UniqueConstraintViolationException('mysql', 'example mysql', [], new Exception('SQLSTATE[23000]: Integrity constraint violation: 1062')),
         );
 
+        $relation->getQuery()->shouldReceive('withSavepointIfNeeded')->once()->andReturnUsing(function ($scope) {
+            return $scope();
+        });
         $relation->getQuery()->shouldReceive('where')->once()->with(['foo'])->andReturn($relation->getQuery());
         $relation->getQuery()->shouldReceive('first')->once()->with()->andReturn($model = m::mock(Model::class));
 
@@ -244,6 +247,9 @@ public function testCreateOrFirstMethodWithValuesFindsFirstModel()
             new UniqueConstraintViolationException('mysql', 'example mysql', [], new Exception('SQLSTATE[23000]: Integrity constraint violation: 1062')),
         );
 
+        $relation->getQuery()->shouldReceive('withSavepointIfNeeded')->once()->andReturnUsing(function ($scope) {
+            return $scope();
+        });
         $relation->getQuery()->shouldReceive('where')->once()->with(['foo' => 'bar'])->andReturn($relation->getQuery());
         $relation->getQuery()->shouldReceive('first')->once()->with()->andReturn($model = m::mock(Model::class));
 
@@ -259,6 +265,9 @@ public function testCreateOrFirstMethodCreatesNewMorphModel()
         $model->shouldReceive('setAttribute')->once()->with('morph_type', get_class($relation->getParent()));
         $model->shouldReceive('save')->once()->andReturn(true);
 
+        $relation->getQuery()->shouldReceive('withSavepointIfNeeded')->once()->andReturnUsing(function ($scope) {
+            return $scope();
+        });
         $relation->getQuery()->shouldReceive('where')->never();
         $relation->getQuery()->shouldReceive('first')->never();
 
@@ -274,6 +283,9 @@ public function testCreateOrFirstMethodWithValuesCreatesNewMorphModel()
         $model->shouldReceive('setAttribute')->once()->with('morph_type', get_class($relation->getParent()));
         $model->shouldReceive('save')->once()->andReturn(true);
 
+        $relation->getQuery()->shouldReceive('withSavepointIfNeeded')->once()->andReturnUsing(function ($scope) {
+            return $scope();
+        });
         $relation->getQuery()->shouldReceive('where')->never();
         $relation->getQuery()->shouldReceive('first')->never();
 

tests/Integration/Database/EloquentBelongsToManyTest.php

@@ -629,6 +629,19 @@ public function testCreateOrFirstUnrelatedExisting()
         $this->assertTrue($tag->is($post->tagsUnique()->first()));
     }
 
+    public function testCreateOrFirstWithinTransaction()
+    {
+        $post = Post::create(['title' => Str::random()]);
+
+        $tag = UniqueTag::create(['name' => Str::random()]);
+
+        $post->tagsUnique()->attach(UniqueTag::all());
+
+        DB::transaction(function () use ($tag, $post) {
+            $this->assertEquals($tag->id, $post->tagsUnique()->createOrFirst(['name' => $tag->name])->id);
+        });
+    }
+
     public function testFirstOrNewMethodWithValues()
     {
         $post = Post::create(['title' => Str::random()]);

tests/Integration/Database/EloquentHasManyTest.php

@@ -5,6 +5,7 @@
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Database\Eloquent\Relations\HasOne;
+use Illuminate\Support\Facades\DB;
 use Illuminate\Support\Facades\Schema;
 use Illuminate\Support\Str;
 
@@ -70,6 +71,21 @@ public function testCreateOrFirst()
         $this->assertTrue($post1->is($post2));
         $this->assertCount(1, $user->posts()->get());
     }
+
+    public function testCreateOrFirstWithinTransaction()
+    {
+        $user = EloquentHasManyTestUser::create();
+
+        $post1 = $user->posts()->create(['title' => Str::random()]);
+
+        DB::transaction(function () use ($user, $post1) {
+            $post2 = $user->posts()->createOrFirst(['title' => $post1->title]);
+
+            $this->assertTrue($post1->is($post2));
+        });
+
+        $this->assertCount(1, $user->posts()->get());
+    }
 }
 
 class EloquentHasManyTestUser extends Model

tests/Integration/Database/MySql/DatabaseEloquentMySqlIntegrationTest.php

@@ -4,6 +4,7 @@
 
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
 use Illuminate\Support\Facades\Schema;
 
 class DatabaseEloquentMySqlIntegrationTest extends MySqlTestCase
@@ -57,6 +58,22 @@ public function testCreateOrFirst()
 
         $this->assertSame('Nuno Maduro', $user4->name);
     }
+
+    public function testCreateOrFirstWithinTransaction()
+    {
+        $user1 = DatabaseEloquentMySqlIntegrationUser::createOrFirst(['email' => '[email protected]']);
+
+        DB::transaction(function () use ($user1) {
+            $user2 = DatabaseEloquentMySqlIntegrationUser::createOrFirst(
+                ['email' => '[email protected]'],
+                ['name' => 'Taylor Otwell']
+            );
+
+            $this->assertEquals($user1->id, $user2->id);
+            $this->assertSame('[email protected]', $user2->email);
+            $this->assertNull($user2->name);
+        });
+    }
 }
 
 class DatabaseEloquentMySqlIntegrationUser extends Model

tests/Integration/Database/Postgres/DatabaseEloquentPostgresIntegrationTest.php

@@ -4,6 +4,7 @@
 
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
 use Illuminate\Support\Facades\Schema;
 
 class DatabaseEloquentPostgresIntegrationTest extends PostgresTestCase
@@ -57,6 +58,22 @@ public function testCreateOrFirst()
 
         $this->assertSame('Nuno Maduro', $user4->name);
     }
+
+    public function testCreateOrFirstWithinTransaction()
+    {
+        $user1 = DatabaseEloquentPostgresIntegrationUser::create(['email' => '[email protected]']);
+
+        DB::transaction(function () use ($user1) {
+            $user2 = DatabaseEloquentPostgresIntegrationUser::createOrFirst(
+                ['email' => '[email protected]'],
+                ['name' => 'Taylor Otwell']
+            );
+
+            $this->assertEquals($user1->id, $user2->id);
+            $this->assertSame('[email protected]', $user2->email);
+            $this->assertNull($user2->name);
+        });
+    }
 }
 
 class DatabaseEloquentPostgresIntegrationUser extends Model

tests/Integration/Database/SqlServer/DatabaseEloquentSqlServerIntegrationTest.php

@@ -4,6 +4,7 @@
 
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
 use Illuminate\Support\Facades\Schema;
 
 class DatabaseEloquentSqlServerIntegrationTest extends SqlServerTestCase
@@ -57,6 +58,22 @@ public function testCreateOrFirst()
 
         $this->assertSame('Nuno Maduro', $user4->name);
     }
+
+    public function testCreateOrFirstWithinTransaction()
+    {
+        $user1 = DatabaseEloquentSqlServerIntegrationUser::createOrFirst(['email' => '[email protected]']);
+
+        DB::transaction(function () use ($user1) {
+            $user2 = DatabaseEloquentSqlServerIntegrationUser::createOrFirst(
+                ['email' => '[email protected]'],
+                ['name' => 'Taylor Otwell']
+            );
+
+            $this->assertEquals($user1->id, $user2->id);
+            $this->assertSame('[email protected]', $user2->email);
+            $this->assertNull($user2->name);
+        });
+    }
 }
 
 class DatabaseEloquentSqlServerIntegrationUser extends Model