Regression in 2.9 constantly outputting table differences

[cs278]

Bug Report

Q	A
BC Break	yes
Version	2.9.*

Summary

I've tried to upgrade a project to DBAL 2.9.2 from 2.8.1, however the Doctrine bundle schema diff command constantly outputs schema changes. This is triggered as we've overloaded the default datetime type with datetime_immutable.

Current behaviour

Schema diff constantly generates the following query:

ALTER TABLE test CHANGE dt dt DATETIME NOT NULL COMMENT '(DC2Type:datetime_immutable)'

How to reproduce

Given schema:

CREATE TABLE test (dt DATETIME NOT NULL COMMENT '(DC2Type:datetime_immutable)') DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE = InnoDB;

Running the following, will exit 0 on 2.8.1 and error on 2.9.2.

<?php

use Doctrine\DBAL\Schema\Comparator;
use Doctrine\DBAL\Schema\Schema;
use Doctrine\DBAL\Types\Type;
use Doctrine\DBAL\DriverManager;

require 'vendor/autoload.php';

Type::overrideType('datetime', \Doctrine\DBAL\Types\DateTimeImmutableType::class);

$conn = DriverManager::getConnection([
    'url' => 'mysql://root@127.0.0.1:3306/main',
]);

$conn->connect();

$platform = $conn->getDatabasePlatform();
$schemaManager = $conn->getSchemaManager();

$schema1 = $schemaManager->createSchema();

$schema2 = new Schema();
$table2 = $schema2->createTable('test');
$table2->addColumn('dt', 'datetime');
$diff = Comparator::compareSchemas($schema1, $schema2)->toSql($platform);

var_dump($diff);

exit($diff === [] ? 0 : 1);

Expected behaviour

No update queries should be generated.

Patch

Cause: dca1465#diff-6a252b2e905db4e03fc6a121a41e6466L415

This fixes the problem, not entirely sure if this is the correct resolution though.

diff --git a/lib/Doctrine/DBAL/Schema/Comparator.php b/lib/Doctrine/DBAL/Schema/Comparator.php
index 8297e05..33ee482 100644
--- a/lib/Doctrine/DBAL/Schema/Comparator.php
+++ b/lib/Doctrine/DBAL/Schema/Comparator.php
@@ -11,6 +11,7 @@
 use function array_shift;
 use function array_unique;
 use function count;
+use function get_class;
 use function strtolower;
 
 /**
@@ -419,7 +420,11 @@ public function diffColumn(Column $column1, Column $column2)
 
         $changedProperties = [];
 
-        foreach (['type', 'notnull', 'unsigned', 'autoincrement'] as $property) {
+        if (get_class($properties1['type']) !== get_class($properties2['type'])) {
+            $changedProperties[] = 'type';
+        }
+
+        foreach (['notnull', 'unsigned', 'autoincrement'] as $property) {
             if ($properties1[$property] === $properties2[$property]) {
                 continue;
             }

[Ocramius]

@cs278 is it possible to isolate this into a test case?

[cs278]

@Ocramius I guess so, as the root cause is that the Type is not the same instance. Does the patch seem reasonable or should I be comparing types in another way?

[Ocramius]

Does the patch seem reasonable

No idea: I'd need a test first.

[garret-gunter]

I created a merge request for this. #3456

I added two unit tests. Do you want to see a more thorough test case?

[morozov]

Fixed by #3456.

[SenseException]

@garret-gunter @morozov Sounds like this issue can be closed now, right?

[morozov]

@SenseException, yes. Thank you.

[github-actions]

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