Calling add_settings_section() without callback function throws notices

[lightningspirit]

Calling add_settings_section() without a callback function should be possible, since a lot of settings section don't need *anything* special between the <h3> tags and the input settings.

This patch aloows people to call without providing a custom function for that purpose.

Changind do_settings_section().

[obenland]

One might as well just pass '__return_false'.

[lightningspirit]

Although those functions can be used anywhere, in my opinion their purpose is to be used in the core mainly.

__return_false, __return_true, __return_zero and __return_empty_array are not so well-known, besides there are no codex entry for them...

If you can pass false to register_post_type *callbacks* and a lot of other functions why not here too? It's just to make things easier for developers.

[nacin]

The __return methods are designed for plugin usage, in particular as callbacks. Mainly for actions and filters, but this works too.

I usually pass __return_false here as well, but I also find it to be lame, and agree with this patch.

[ryan]

In [21742]:

Make the callback optional for add_settings_section(). Props lightningspirit. fixes #21630