empty block at foot of dashboard block admin page

hummm
block.admin.inc, we add system_main key

 // Do not allow disabling the main system content block.
  $form['blocks']['system_main']['region']['#required'] = TRUE;

Not sure what is this system_main blocks, any clues ?

btw, if we check if the key is present before trying to force the requiered = TRUE, it could resolve the issue. But i'am really not sure about that.

This is fallout from #140783: A select list without #default_value always passes form validation (and the cleanup patch there at http://drupal.org/node/140783#comment-3501422 fixed this plus several other things) - however, that issue turned into a long mess and it will take time to sort it all out; it seems very reasonable to fix this one separately :)

'system_main' is the main content block, which is usually present on the form when the Block module uses it, but not when the Dashboard module reuses it, so indeed, checking isset() is a reasonable fix.

I'd probably suggest checking isset($form['blocks']['system_main']['region']) as the patch at the above issue did, though - might as well go all the way and check as deep in the array as we want to go.

Also, it's minor, but:

-  // Do not allow disabling the main system content block.
-  $form['blocks']['system_main']['region']['#required'] = TRUE;
-

Please don't remove the blank line at the end. It's needed to logically separate this block of code from what comes after it.

With those changes I'd say this is RTBC - thanks!

Looks perfect.

Committed to CVS HEAD. Thanks.