Add guard clause

It maybe happen that the SQL COMMIT statement is successful, but then
something goes wrong. In that kind of case, you do not want to attempt a
rollback.

This was implemented in UnitOfWork::commit(), but for some reason not in
the similar EntityManager methods.

src/EntityManager.php

@@ -259,7 +259,9 @@ public function transactional($func)
         } finally {
             if (! $successful) {
                 $this->close();
-                $this->conn->rollBack();
+                if ($this->conn->isTransactionActive()) {
+                    $this->conn->rollBack();
+                }
             }
         }
     }
@@ -285,7 +287,9 @@ public function wrapInTransaction(callable $func)
         } finally {
             if (! $successful) {
                 $this->close();
-                $this->conn->rollBack();
+                if ($this->conn->isTransactionActive()) {
+                    $this->conn->rollBack();
+                }
             }
         }
     }

tests/Tests/ORM/EntityManagerTest.php

@@ -29,6 +29,7 @@
 use Exception;
 use Generator;
 use InvalidArgumentException;
+use PHPUnit\Framework\Assert;
 use stdClass;
 use TypeError;
 
@@ -409,6 +410,33 @@ public function rollBack(): bool
         }
     }
 
+    /** @dataProvider entityManagerMethodNames */
+    public function testItDoesNotAttemptToRollbackIfNoTransactionIsActive(string $methodName): void
+    {
+        $entityManager = new EntityManagerMock(
+            new class extends ConnectionMock {
+                public function commit(): bool
+                {
+                    throw new Exception('Commit exception that happens after doing the actual commit');
+                }
+
+                public function rollBack(): bool
+                {
+                    Assert::fail('Should not attempt to rollback if no transaction is active');
+                }
+
+                public function isTransactionActive(): bool
+                {
+                    return false;
+                }
+            }
+        );
+
+        $this->expectExceptionMessage('Commit exception');
+        $entityManager->$methodName(static function (): void {
+        });
+    }
+
     /** @return Generator<string, array{string}> */
     public function entityManagerMethodNames(): Generator
     {