Hard deprecate functions deprecated before WP 3.7.0

[peterwilsoncc]

There are several of soft deprecated functions in wp-includes/deprecated.php.

It's safe to hard deprecate those listed as deprecated prior to the introduction of automatic updates in version 3.7.

Several tests will need to be removed, others will need to be modified to use the non-deprecated equivalent when using pre-3.7 deprecated functions to test functions deprecated in 3.7 or later.

The initial patch removes the functions but needs a refresh to modify the tests.

[jorbin]

Before this goes in, we should scan the plugin repo for uses of these functions. There should also be a communication plan.

[jorbin]

get_postdata

[Frank Klein]

I propose to keep this ticket as an overall way to track progress, while breaking out into separate tickets for each hard-deprecated function. This would make it easier to keep all the communications around a particular function together, as some are still used in plugins or themes in the .org repositories.

The scan results posted above are a good place to start, but they'd need to be more precise if possible. They include one plugin no longer available for download (presstest), and two false positives (fb-instant-articles and campuspress-theme-check).

For these plugins, there should be a discussion on how long to give authors to update them, and what the cut off point would be for authors that do not respond. The spam-words plugin for example hasn't been updated in 13 years, and others are similarly outdated.

[jdgrimes]

Replying to jorbin:

Before this goes in, we should scan the plugin repo for uses of these functions.

I have a slurp of the directory on hand if aid is needed as far as that goes. (Though pointers on the search strings to run for best results are welcome.)

[SergeyBiryukov]

Related: #41520

[peterwilsoncc]

@pento has suggested moving the deprecated functions to a plugin and integrating it with WSOD recovery in #44458.

Moving this to future release as this needs to wait until the WSOD code is in core.

[spacedmonkey]

I perf making this an option for users. See #41520

[SergeyBiryukov]

Related: #49957