Fixed schema comparison attempting to remove double foreign keys.

Author: mickverm

src/Schema/Comparator.php

@@ -275,14 +275,17 @@ public function compareTables(Table $oldTable, Table $newTable): TableDiff
             foreach ($newForeignKeys as $newKey => $newForeignKey) {
                 if ($this->diffForeignKey($oldForeignKey, $newForeignKey) === false) {
                     unset($oldForeignKeys[$oldKey], $newForeignKeys[$newKey]);
-                } else {
-                    if (strtolower($oldForeignKey->getName()) === strtolower($newForeignKey->getName())) {
-                        $droppedForeignKeys[$oldKey] = $oldForeignKey;
-                        $addedForeignKeys[$newKey]   = $newForeignKey;
+                    continue 2;
+                }
 
-                        unset($oldForeignKeys[$oldKey], $newForeignKeys[$newKey]);
-                    }
+                if (strtolower($oldForeignKey->getName()) !== strtolower($newForeignKey->getName())) {
+                    continue;
                 }
+
+                $droppedForeignKeys[$oldKey] = $oldForeignKey;
+                $addedForeignKeys[$newKey]   = $newForeignKey;
+
+                unset($oldForeignKeys[$oldKey], $newForeignKeys[$newKey]);
             }
         }
 

tests/Functional/Schema/DoubleForeignKeyConstraintTest.php

@@ -0,0 +1,92 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\DBAL\Tests\Functional\Schema;
+
+use Doctrine\DBAL\Platforms\DB2Platform;
+use Doctrine\DBAL\Platforms\OraclePlatform;
+use Doctrine\DBAL\Schema\AbstractSchemaManager;
+use Doctrine\DBAL\Schema\Column;
+use Doctrine\DBAL\Schema\ForeignKeyConstraint;
+use Doctrine\DBAL\Schema\PrimaryKeyConstraint;
+use Doctrine\DBAL\Schema\Table;
+use Doctrine\DBAL\Tests\FunctionalTestCase;
+use Doctrine\DBAL\Types\Types;
+
+class DoubleForeignKeyConstraintTest extends FunctionalTestCase
+{
+    private AbstractSchemaManager $schemaManager;
+
+    protected function setUp(): void
+    {
+        $this->schemaManager = $this->connection->createSchemaManager();
+    }
+
+    public function testDoubleForeignKeyConstraint(): void
+    {
+        $platform = $this->connection->getDatabasePlatform();
+        if ($platform instanceof DB2Platform || $platform instanceof OraclePlatform) {
+            self::markTestSkipped('DB2 and Oracle do not allow multiple FKs with the same columns.');
+        }
+
+        $articles = Table::editor()
+            ->setUnquotedName('articles')
+            ->setColumns(
+                Column::editor()
+                    ->setUnquotedName('id')
+                    ->setTypeName(Types::INTEGER)
+                    ->create(),
+            )
+            ->setPrimaryKeyConstraint(
+                PrimaryKeyConstraint::editor()
+                    ->setUnquotedColumnNames('id')
+                    ->create(),
+            )
+            ->create();
+
+        $orders = Table::editor()
+            ->setUnquotedName('orders')
+            ->setColumns(
+                Column::editor()
+                    ->setUnquotedName('id')
+                    ->setTypeName(Types::INTEGER)
+                    ->create(),
+                Column::editor()
+                    ->setUnquotedName('article_id')
+                    ->setTypeName(Types::INTEGER)
+                    ->create(),
+            )
+            ->setForeignKeyConstraints(
+                ForeignKeyConstraint::editor()
+                    ->setUnquotedName('articles_fk')
+                    ->setUnquotedReferencingColumnNames('article_id')
+                    ->setUnquotedReferencedTableName('articles')
+                    ->setUnquotedReferencedColumnNames('id')
+                    ->create(),
+                ForeignKeyConstraint::editor()
+                    ->setUnquotedName('articles_fk_2')
+                    ->setUnquotedReferencingColumnNames('article_id')
+                    ->setUnquotedReferencedTableName('articles')
+                    ->setUnquotedReferencedColumnNames('id')
+                    ->create(),
+            )
+            ->create();
+
+        $this->dropTableIfExists('orders');
+        $this->dropTableIfExists('articles');
+
+        $this->connection->createSchemaManager()
+            ->createTable($articles);
+        $this->connection->createSchemaManager()
+            ->createTable($orders);
+
+        $onlineTable = $this->schemaManager->introspectTable('orders');
+
+        self::assertTrue(
+            $this->schemaManager->createComparator()
+                ->compareTables($orders, $onlineTable)
+                ->isEmpty(),
+        );
+    }
+}