Rearrange link and tabs not displaying

Did you even test your RC ??

After installing your module, I noticed nothing happens...no links added to if I choose "Link" in the settings. No tabs added if I choose "Tabs". First, there's this problem (easily patched, luckily):

function rearrange_child_pages_access($nid, $type) {
  $has_children = db_result(db_query('SELECT ml.has_children FROM {book} b INNER JOIN {menu_links} ml ON b.mlid = ml.mlid WHERE b.nid = %d', $node)); 

Your parameter is $nid, but you use $node in your query. Not a big deal, but it breaks your entire module, as the function will always return FALSE.

Then, you call the book_admin_edit function in your hook_menu()...This always triggers an error, because the file that defines this function is not included.

Change your _menu() hook to include book.admin.inc:

$items['node/%node/rearrange'] = array(
    'access callback' => 'rearrange_child_pages_access',
    'access arguments' => array(1, 'tab'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('book_admin_edit', 1),
    'title' => 'Rearrange child pages',
    'file' => 'book.admin.inc',
    'file path' => drupal_get_path('module', 'book'),
    'weight' => 5,
    'type' => MENU_LOCAL_TASK,
);

I'm going to try it one more time, see if it works after patches are applied.