Ensure unique association aliases for self-referencing keys

src/Command/ModelCommand.php

@@ -1587,7 +1587,16 @@ protected function ensureAliasUniqueness(array $associations): array
             foreach ($associationsPerType as $k => $association) {
                 $alias = $association['alias'];
                 if (in_array($alias, $existing, true)) {
-                    $alias = $this->createAssociationAlias($association);
+                    // Derive a unique alias by appending a numeric suffix.
+                    // Self-referencing keys (e.g. `system_id` on `systems`)
+                    // would otherwise yield the same colliding alias again.
+                    $base = $this->createAssociationAlias($association);
+                    $alias = $base;
+                    $i = 1;
+                    while (in_array($alias, $existing, true)) {
+                        $i++;
+                        $alias = $base . $i;
+                    }
                 }
                 $existing[] = $alias;
                 if (empty($association['className'])) {

tests/TestCase/Command/ModelCommandTest.php

@@ -282,6 +282,35 @@ public function testApplyAssociationsConcreteClass(): void
         $this->assertEquals($original, $new);
     }
 
+    /**
+     * A non-foreign-key column matching the table name (e.g. `system_id` on
+     * `systems`) must not produce duplicate aliases that break baking.
+     *
+     * @return void
+     */
+    public function testGetAssociationsEnsuresUniqueAliasForSelfReferencingKey(): void
+    {
+        $systems = $this->getTableLocator()->get('Systems');
+
+        $command = new ModelCommand();
+        $command->connection = 'test';
+        $args = new Arguments([], [], []);
+        $io = $this->createStub(ConsoleIo::class);
+        $result = $command->getAssociations($systems, $args, $io);
+
+        $belongsToAliases = array_column($result['belongsTo'], 'alias');
+        $hasManyAliases = array_column($result['hasMany'], 'alias');
+        $allAliases = array_merge($belongsToAliases, $hasManyAliases);
+
+        $this->assertContains('Systems', $belongsToAliases);
+        $this->assertContains('Systems2', $hasManyAliases);
+        $this->assertSame($allAliases, array_unique($allAliases), 'Association aliases must be unique.');
+
+        // Applying the deduplicated associations must not throw.
+        $command->applyAssociations($systems, $result);
+        $this->assertSame(['Systems', 'Systems2'], $systems->associations()->keys());
+    }
+
     /**
      * Test getAssociations
      *

tests/schema.php

@@ -587,6 +587,17 @@
             'unique_self_referencing_parent' => ['type' => 'unique', 'columns' => ['parent_id']],
         ],
     ],
+    // "systems" has a "system_id" column that is not a real foreign key.
+    // It would otherwise produce duplicate "Systems" belongsTo/hasMany aliases.
+    [
+        'table' => 'systems',
+        'columns' => [
+            'id' => ['type' => 'integer'],
+            'system_id' => ['type' => 'string', 'length' => 255, 'null' => false],
+            'name' => ['type' => 'string', 'length' => 255, 'null' => true],
+        ],
+        'constraints' => ['primary' => ['type' => 'primary', 'columns' => ['id']]],
+    ],
     // "news" is both singular and plural - tests variable collision fix
     [
         'table' => 'news',