Module tests with extending submodule tests not included correctly.

Say we have the following things:
/sites/all/modules/mymodule/mymodule.test:

class MyModuleTestHelper extends DrupalWebTestCase {
  function assertBlah() {
    ...
  }

/sites/all/modules/mymodule/mysubmodule/mysubmodule.test:

class MySubModuleTest extends MyModuleTestHelper {
  function setUp() {
    ...
  }
  
  function testFoo() {
    $this->assertBlah(...);
  }
}

Before this would work without problem. On the latest DRUPAL-6--2 CVS code, it causes a PHP fatal error with a class does not exist on the test selection page.

The problem is that when scanning for tests in simpletest_test_get_all_classes() the file_scan_directory is resursive and finds the submodule test files first and includes them before the base module's test files.

  $files = module_rebuild_cache();
  foreach ($files as $file) {
    $directory = dirname($file->filename);
    $test_files = file_scan_directory($directory, '\.test$');

We should restrict this to searching for any .test files of the current module directory or any test files in a subfolder of the current module called 'tests' as per the standards:

  $files = module_rebuild_cache();
  foreach ($files as $file) {
    $directory = dirname($file->filename);
    $test_files = file_scan_directory($directory, '\.test$', array('.', '..', 'CVS'), FALSE, FALSE);
    $test_files += file_scan_directory($directory . '/tests', '\.test$')

This allows the test selection screen to work, although there are other bugs so I can't check if the tests actually run.