Support for string $args in wp_get_object_terms() broken in 4.7

[sstoqnov]

It appears that wp_get_object_terms() no longer supports the string version of the $args parameter. Prior to WordPress 4.7 it used to support both string and array values, and there might be multiple plugins and themes that rely on this fact. It's also documented as string|array in the Codex.

After digging a bit I found that this regression has been introduced in [38667] which removed a lot of redundant code.

[tyxla]

Improve initial patch by using wp_parse_args() instead of explode()

[tyxla]

I've updated the patch, to use wp_parse_args() instead of explode(). It's a minimal solution to support string $args, without default args. To further clarify: prior to 4.7, default values were specified in the wp_parse_args() call.

[ocean90]

Does someone want to work on a unit test for this?

[tyxla]

Sure thing, I will in a bit.

[tyxla]

Add unit test to verify support for string $args.

[tyxla]

39215.3.patch includes a unit test that verifies $args can also be a string.

[swissspidy]

Note that the is_string( $args ) check shouldn't be needed here.

[tyxla]

Note that the is_string( $args ) check shouldn't be needed here.

Since calling wp_parse_args() on an array $args is completely unnecessary, my point was to avoid any overhead that calling wp_parse_args() on that array would cause. But you're right that wp_parse_args() will work just fine for arrays as well, so I'm attaching an updated patch.

[tyxla]

Remove an unnecessary is_string() check

[dd32]

In 39578:

Taxonomy: Restore the ability to use string-based $args in wp_get_object_terms().

Props tyxla.
Fixes #39215

[dd32]

re-opening for 4.7.1

[dd32]

In 39611:

Taxonomy: Restore the ability to use string-based $args in wp_get_object_terms().

Props tyxla.
Merges [39578] to the 4.7 branch.
Fixes #39215.