fix duplicate primary keys for tables without models

lib/Cake/Model/CakeSchema.php

@@ -613,9 +613,16 @@ protected function _columns(&$Obj) {
		$db = $Obj->getDataSource();
		$fields = $Obj->schema(true);

		$hasPrimaryAlready = false;
		foreach ($fields as $value) {
			if (isset($value['key']) && $value['key'] === 'primary') {
				$hasPrimaryAlready = true;
			}
		}

		$columns = array();
		foreach ($fields as $name => $value) {
			if ($Obj->primaryKey === $name) {
			if ($Obj->primaryKey === $name && !$hasPrimaryAlready && !isset($value['key'])) {
				$value['key'] = 'primary';
			}
			if (!isset($db->columns[$value['type']])) {

lib/Cake/Test/Case/Model/CakeSchemaTest.php

@@ -363,6 +363,39 @@ class SchemaCrossDatabaseFixture extends CakeTestFixture {
	);
}

/**
 * NonConventionalPrimaryKeyFixture class
 *
 * @package       Cake.Test.Case.Model
 */
class NonConventionalPrimaryKeyFixture extends CakeTestFixture {

/**
 * name property
 *
 * @var string
 */
	public $name = 'NonConventional';

/**
 * table property
 *
 * @var string
 */
	public $table = 'non_conventional';

/**
 * fields property
 *
 * @var array
 */
	public $fields = array(
		'version_id' => array('type' => 'integer', 'key' => 'primary'),
		'id' => array('type' => 'integer'),
		'name' => 'string'
	);
}

/**
 * SchemaPrefixAuthUser class
 *
@@ -649,6 +682,36 @@ public function testSchemaReadWithCrossDatabase() {
		$fixture->drop($db);
	}

/**
 * testSchemaRead method when a primary key is on a non-conventional column
 *
 * @return void
 */
	public function testSchemaReadWithNonConventionalPrimaryKey() {
		$db = ConnectionManager::getDataSource('test');
		$fixture = new NonConventionalPrimaryKeyFixture();
		$fixture->create($db);

		$read = $this->Schema->read(array(
			'connection' => 'test',
			'name' => 'TestApp',
			'models' => false
		));
		$fixture->drop($db);

		$has_table = isset($read['tables']['non_conventional']);
		$this->assertTrue($has_table, 'non_conventional table should appear');
		if ($has_table) {
			$version_id_has_key = isset($read['tables']['non_conventional']['version_id']['key']);
			$this->assertTrue($version_id_has_key, 'version_id key should be set');
			if ($version_id_has_key) {
				$version_id_key_is_primary = $read['tables']['non_conventional']['version_id']['key'] === 'primary';
				$this->assertTrue($version_id_key_is_primary, 'version_id key should be primary');
			}
			$this->assertFalse(isset($read['tables']['non_conventional']['id']['key']), 'id key should not be set');
		}
	}

/**
 * test that tables are generated correctly
 *