Deprecate wp_slash_strings_only() in favour of wp_slash()

[ocean90]

Since [48433] wp_slash() no longer changes non-string types which was the main reason for the introduction of wp_slash_strings_only() in [46454]. To avoid confusion we should deprecate wp_slash_strings_only().

[ayeshrajans]

Deprecates wp_slash_strings_only() and addslashes_strings_only() functions, and then replaces the single use of those functions with wp_slash; Tests: ​https://travis-ci.com/github/Ayesh/wordpress-develop/builds

[ayeshrajans]

Posted wrong build URL above. Correct one: ​https://travis-ci.com/github/Ayesh/wordpress-develop/builds/183711321

[SergeyBiryukov]

In 49188:

Formatting: Deprecate wp_slash_strings_only() in favor of wp_slash().

The reason for introducing wp_slash_strings_only() in [46454] was to keep non-string values untouched.

Later, wp_slash() itself was updated in [48433] to prevent changing non-string values.

To avoid confusion, wp_slash_strings_only() is now deprecated.

Props ayeshrajans, ocean90.
Fixes #50635.

[garrett-eclipse]

Should references of wp_slash_strings_only be removed from the WordPress Importer phpunit data?
When you install from svn the wordpress-importer dir is installed to the tests/phpunit/data/plugins and the wordpress-importer/class-wp-import.php contains references to wp_slash_strings_only, as well there's a pluggable wp_slash_strings_only function in the wordpress-importer/compat.php.
Thanks

[SergeyBiryukov]

Replying to garrett-eclipse:

Should references of wp_slash_strings_only be removed from the WordPress Importer phpunit data?
When you install from svn the wordpress-importer dir is installed to the tests/phpunit/data/plugins and the wordpress-importer/class-wp-import.php contains references to wp_slash_strings_only, as well there's a pluggable wp_slash_strings_only function in the wordpress-importer/compat.php.

Good catch, thanks! I think the plugin can be left as is for now, as it aims to be compatible with WP 3.7+, and the fix for wp_slash() to handle non-string values is only available since WP 5.5.

That said, the plugin could probably be updated to call wp_slash() on WP 5.5+, and wp_slash_strings_only() on older versions.

[garrett-eclipse]

Replying to SergeyBiryukov:

That said, the plugin could probably be updated to call wp_slash() on WP 5.5+, and wp_slash_strings_only() on older versions.

Thanks @SergeyBiryukov I've opened a ticket on the plugin repo here;
​https://github.com/WordPress/wordpress-importer/issues/83