Make it easier to check theme support

[obenland]

Currently we don't make it too easy for plugins (and themes I suppose) to get access to the information passed in the second argument to add_theme_support().

To get more information about a theme's support for post thumbnails for example, a plugin would have to assign the return value of get_theme_support() to a variable and then access the value stored in the first key of the returned array:

<?php
$support = get_theme_support( 'post-thumbnails' );
$actual_support = $support[0];

While this is not ideal for core features that themes need to register support for, it gets painful quickly when themes and plugins want to deal with information coupled to a custom feature.

[obenland]

Attached patch merges the array with the array of information, with the array of information. The result would look like this:

<?php
// get_theme_support('html5');

array (size=4)
  0 => 
    array (size=3)
      0 => string 'search-form' (length=11)
      1 => string 'comment-form' (length=12)
      2 => string 'comment-list' (length=12)
  1 => string 'search-form' (length=11)
  2 => string 'comment-form' (length=12)
  3 => string 'comment-list' (length=12)

[obenland]

Adds some documentation and makes sure current_theme_supports() always returns a boolean.

[kirasong]

Refreshed.

[kirasong]

Hi obenland!

I'm sorry it took so long for you to get a reply!

I've refreshed the patch​ so that it applies cleanly on trunk, and tested it. It appears to work as advertised.

The duplication of returned information seems a little strange, but back-compat often is.

@nacin noted in the chat linked above that a whitelist for support may be appropriate.