Add test for Column object with updateColumn()

- Tests that updateColumn() works correctly when passed a Column object
- Addresses review feedback to ensure Column type support is tested

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: dereuromark

tests/TestCase/Db/Adapter/MysqlAdapterTest.php

@@ -1082,6 +1082,25 @@ public function testChangeColumnWithPreserveUnspecifiedTrue()
         $this->assertEquals('YES', $rows[1]['Null']);
     }
 
+    public function testUpdateColumnWithColumnObject()
+    {
+        $table = new Table('t', [], $this->adapter);
+        $table->addColumn('column1', 'string', ['default' => 'test', 'limit' => 100, 'null' => false])
+              ->save();
+
+        // Use updateColumn with a Column object
+        $newColumn = new Column();
+        $newColumn->setName('column1')
+                  ->setType('string')
+                  ->setLimit(255)
+                  ->setNull(true);
+        $table->updateColumn('column1', $newColumn)->save();
+
+        $rows = $this->adapter->fetchAll('SHOW COLUMNS FROM t');
+        $this->assertEquals('varchar(255)', $rows[1]['Type']);
+        $this->assertEquals('YES', $rows[1]['Null']);
+    }
+
     public function testChangeColumnEnum()
     {
         $table = new Table('t', [], $this->adapter);