[BUGFIX] Ensure Comparator knows the current platform

Doctrine DBAL 3.x has been introduced into TYPO3 v12
with #96287 and raised over the time, adding the one
or other deprecation and dual code branches and some
compat layers.

The `\Doctrine\DBAL\Schema\Comparator::compareSchemas()`
for example is still static and instantiaces itself,
and therefore not properly handing over the platform.
The missing platform does not execute the new way of
using `AbstractPlatform::columnsEqual()`, but renders
the platform specific handlings useless - specially
added for MySQL based platforms, for example the
datbase type `TEXT` length check and comparision.

This change passes the platform down to the inner
`Comparator` instance to ensure that the platform
specific handling can work. To avoid the new way
using the `AbstractPlatform::columnsEqual()` which
introduces incompatible checks for now, that method
is overriden and the `diffColumn()` check used.

That allows the proper TEXT sub-type handling with
MySQL and MariaDB while supressing noise for now.

Note: This is also done currently in TYPO3 v13.

Resolves: #103348
Related: #96287 (Doctrine DBAL 3.2)
Releases: 12.4
Change-Id: If130c73ff122d09a50158bc3ac53f28f9a4eb749
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83457
Reviewed-by: Garvin Hicking <gh@faktor-e.de>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christophe Monard <contact@cmonard.fr>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Christophe Monard <contact@cmonard.fr>
Reviewed-by: Developer Archriss <typo3@archriss.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Garvin Hicking <gh@faktor-e.de>
Tested-by: Developer Archriss <typo3@archriss.com>

typo3/sysext/core/Classes/Database/Schema/Comparator.php

@@ -18,6 +18,7 @@
 namespace TYPO3\CMS\Core\Database\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
+use Doctrine\DBAL\Platforms\MariaDBPlatform;
 use Doctrine\DBAL\Platforms\MySQLPlatform;
 use Doctrine\DBAL\Schema\Column;
 use Doctrine\DBAL\Schema\ForeignKeyConstraint;
@@ -111,7 +112,7 @@ public function diffColumn(Column $column1, Column $column2)
         $changedProperties = parent::diffColumn($column1, $column2);
 
         // Only MySQL has variable length versions of TEXT/BLOB
-        if (!$this->databasePlatform instanceof MySQLPlatform) {
+        if (!($this->databasePlatform instanceof MariaDBPlatform || $this->databasePlatform instanceof MySQLPlatform)) {
             return $changedProperties;
         }
 
@@ -131,6 +132,15 @@ public function diffColumn(Column $column1, Column $column2)
         return array_unique($changedProperties);
     }
 
+    /**
+     * @todo TYPO3 v13 needs to properly handle the columnsEqual way, so we use the old column comparison here to
+     *       avoid noisy and incorrect comparison for now leading to endless loop.
+     */
+    public function columnsEqual(Column $column1, Column $column2): bool
+    {
+        return $this->diffColumn($column1, $column2) === [];
+    }
+
     /**
      * Returns a SchemaDiff object containing the differences between the schemas
      * $fromSchema and $toSchema.
@@ -153,9 +163,10 @@ public function diffColumn(Column $column1, Column $column2)
      */
     public static function compareSchemas(
         Schema $fromSchema,
-        Schema $toSchema
+        Schema $toSchema,
+        AbstractPlatform $platform = null
     ) {
-        $comparator       = new self();
+        $comparator       = new self($platform);
         $diff             = new SchemaDiff();
         $diff->fromSchema = $fromSchema;
 

typo3/sysext/core/Classes/Database/Schema/ConnectionMigrator.php

@@ -244,7 +244,7 @@ static function ($assetName) use ($tablesForConnection) {
 
         // Build SchemaDiff and handle renames of tables and columns
         $comparator = GeneralUtility::makeInstance(Comparator::class, $this->connection->getDatabasePlatform());
-        $schemaDiff = $comparator->compareSchemas($fromSchema, $toSchema);
+        $schemaDiff = $comparator->compareSchemas($fromSchema, $toSchema, $this->connection->getDatabasePlatform());
         $schemaDiff = $this->migrateColumnRenamesToDistinctActions($schemaDiff);
 
         if ($renameUnused) {