CS: Fix violations for wp-includes/canonical.php

[jipmoors]

Started working on this at WordCamp London contributor day.

[jipmoors]

Have made some additional changes to make sure wp_parse_url is used on all occasions.

Also to be able to ignore the prepare statement sniff, have made sure all parts of the query have been prepared.
I can imagine this could be a separate patch or at least be a separate commit, but it was in line of fixing the code sniff.

Have ran all unit tests and did not encounter any problems.

[pento]

This is going to need some careful review. A couple of notes from my brief read through:

When moving an assignment out of a conditional block, it should be moved to before the conditional, unless there are significant performance reasons to move it inside.

eg:

if ( is_feed() && ( $id = get_query_var( 'p' ) ) ) {
        // ...
}

would become:

$id = get_query_var( 'p' );
if ( $id && is_feed() ) {
        // ...
}

There's no need to add an empty() call where there wasn't one before.

Similarly, there's no need to add extra type checks. If the value returned by get_permalink() is truth-y, you can assume it's a string.

[jipmoors]

Removed added type-checks and placed declarations before if-statements where possible

[jipmoors]

Please note: I was not (yet) able to test through all the changes myself yet.

[SergeyBiryukov]

This appears to be resolved in [47759] / #49542. I missed that there was an existing ticket, sorry for that!