wp_list_categories() does not accept comma-separated IDs for exclude_tree parameter

[gblsm]

This does not work:

wp_list_categories( array( 'exclude_tree' => '9,10' ) );

as only the category ID=9 and its descendants will be excluded, while ID=10 will be included.
But this works:

wp_list_categories( array( 'exclude_tree' => array( 9, 10 ) ) );

as the categories ID=9, 10 and their descendants will be excluded.

[hnle]

Related: #12981

[tg29359]

The reference page of wp_list_categories() says that,

'exclude_tree'
(array|string) Array or comma/space-separated string of term IDs to exclude, along with their descendants. See get_terms().

​https://developer.wordpress.org/reference/functions/wp_list_categories/

I also think the behavior reported with this ticket does not match the description of the reference.

[gblsm]

Applying wp_parse_id_list() instead of the cast “(array)” seems fixing the bug. The patch does it.

[gblsm]

Related: [34696]

[boonebgorges]

Thanks for the patch, @gblsm. Did you notice this issue because it worked in 4.3 but not in 4.4? It looks like it might be a regression.

[gblsm]

Replying to boonebgorges:

This issue was reported at ​https://ja.forums.wordpress.org/topic/157359 by @odmodm then @tg29359 encouraged opening a ticket.

[boonebgorges]

Thanks for the patches, @gblsm and @hnle. It does look like this is a 4.4 regression, so let's fix for 4.4.1.

[boonebgorges]

In 36005:

Ensure that wp_list_categories() supports comma-separated lists for 'exclude' and 'exclude_tree'.

[34696] introduced a regression whereby comma-separated values for 'exclude'
and 'exclude_tree' would be handled improperly when merging the two parameters,
resulting in category IDs being incorrectly dropped from the combined array.

Props gblsm, hnle.
Fixes #35156.

[boonebgorges]

Reopening for 4.4.1.

[boonebgorges]

In 36006:

Ensure that wp_list_categories() supports comma-separated lists for 'exclude' and 'exclude_tree'.

[34696] introduced a regression whereby comma-separated values for 'exclude'
and 'exclude_tree' would be handled improperly when merging the two parameters,
resulting in category IDs being incorrectly dropped from the combined array.

Merges [36005] to the 4.4 branch.

Props gblsm, hnle.
Fixes #35156.

[gblsm]

Thanks @boonebgorges, I see the version 4.4.1-alpha-36006 has the code fixed!