Provide a way to define the first checkout status programmatically.

Here's the patch. If the variable is not set it defaults to key(commerce_checkout_pages(). Maybe we could expose this on the checkout settings form, though. It could be a select list of "Automatic based on first page" or a specific page. It's more of an advanced item that might just deserve developer documentation.

Here's an updated patch with a test added.

Whoops, synxtax error.

Talked it over with rszrama. The idea will be to change commerce_checkout_first_checkout_page() to invoke page info and alter and get the key, bypassing the checkout pane logic and sorting.

    $checkout_pages = module_invoke_all('commerce_checkout_page_info');
    drupal_alter('commerce_checkout_page_info', $checkout_pages);
    return key($checkout_pages);

Here's a shot at idea from #8. Also updated test to make sure the static cache of panes is empty, showing we bypassed their init for just checking order state info.

This is what I get for trying to write a patch quick. Fix syntax.

+++ b/modules/checkout/commerce_checkout.module
@@ -478,7 +478,12 @@ function commerce_checkout_pages() {
+  $checkout_pages = module_invoke_all('commerce_checkout_page_info');
+  drupal_alter('commerce_checkout_page_info', $checkout_pages);
+  uasort($checkout_pages, 'drupal_sort_weight');

This doesn't work because there might not be a weight.

Here is a new approach that provides a hook to define the default page key.

function hook_commerce_checkout_first_checkout_page() {
  return 'payment';
}

The above code would allow me to ensure an order ends up on Checkout: Payment immediately and no need to fiddle with the checkout router, either. So this is a bonus option beyond performance!

I say, back to RTBC! Test pass, nothing changed in patch.