Move is_ssl() to load.php for use in advanced-cache.php

[johnjamesjacoby]

The is_ssl() function is currently in functions.php making it unavailable to advanced-cache.php.

Batcache and other similar plugins end up copying is_ssl() verbatim for their own use.

I think this is a safe move because:

• Traditional plugins and themes cannot load early enough to need to manually include it
• WordPress does not require_once the functions.php file, meaning anyone trying to pre-include it in their own advanced-cache.php implementation would encounter fatal errors

I think this is a good move because:

• Other common is_ functions are there already (is_multisite(), et all)
• It's a highly useful utility function that developers should feel safe assuming is always available inside of WordPress's runtime, no matter how early

Patch imminent.

[johnjamesjacoby]

Relocate is_ssl() with added @since note

[johnjamesjacoby]

Link to Batcache's duplicated function here:

​https://plugins.trac.wordpress.org/browser/batcache/trunk/advanced-cache.php#L82

[DrewAPicture]

Interesting. I'm a tentative +1 for this.

[johnjamesjacoby]

Does this need anything more to be #blessed?

[ocean90]

Let's add some missing brackets in 35844.1.patch​ and then it can go in.

[DrewAPicture]

In 37677:

Boostrap: Move is_ssl() to wp-includes/load.php.

Moving to load.php introduces parity with other commonly evaluated is_*() functions such as is_admin() or is_multisite(). It also makes is_ssl() available much earlier in the loading process, such as for use in drop-ins like advanced-cache.php.

Props johnjamesjacoby.
Fixes #35844.

[DrewAPicture]

Wouldn't hurt to write up a little dev-note for this, especially if anybody has been audacious enough redefine is_ssl() in a drop-in without a function_exists() check.

[jorbin]

There are enough bootrap/load changes that I think a summary of all of them will make a good single dev-note. Started a draft without much content.