Deleting menu item with sub-items does not update sub-items' parent (with disabled JS)

[JanVoracek]

This bug appears only with disabled JavaScript.

If I create menu with following structure:

• Parent
  • Child 1
    • Child 2

and I delete Child 1, it should look like this:

• Parent
  • Child 2

The problem is that WP does not update the Child 2 's parent (postmeta _menu_item_menu_item_parent) with disabled JavaScript.

[shooper]

Reassign child nav menu items to the grandparent before deleting a nav-menu-item post.

[borekb]

Tried the patch 34803.diff and can confirm that it works for a couple of scenarios that I tested.

[danielbachhuber]

Few points of feedback on the patch:

• I like how the logic is internalised to wp_delete_post(). Seems reasonable.
• Like parent post reassignment immediately preceding in the function call, the procedure should also clear meta cache for affected nav items.
• Needs test coverage.

[shooper]

Also discovered my setting of the $children variable in my nav menu item loop would have broken the cache clearing done for child posts. Updating patch based on @danielbachhuber's comments.

[shooper]

Updated patch that clears child cache & includes test coverage