PHP Notice: Trying to get property 'name' of non-object in wp-admin/includes/class-wp-site-health.php on line 636

[juanlopez4691]

Changes in method get_test_theme_version from class WP_Site_Health introduced an issue that causes a PHP Notice to be thrown in admin page Tools > Site Health:

PHP Notice:  Trying to get property 'name' of non-object in wp-admin/includes/class-wp-site-health.php on line 636

This could be solved changing line 617 from

$active_theme->parent()->name

To

$active_theme->parent() ? $active_theme->parent()->name : ''

Or to

$active_theme->parent_theme

Same problem happens in line 636, same solution applies.

[davidbaumwald]

Hi @juanlopez4691 and welcome to Trac!

I'm removing the needs-testing keyword as testing is requested once a patch has been submitted.

[juanlopez4691]

Ah! Thanks a lot @davidbaumwald. Sorry, this is my first attempt to contribute a fix.

But, why the change of version? The reported issue happens because of a change introduced in version 5.4.

[mukesh27]

Hi there!

Replicated the same issue when anyone removes the parent theme from the theme directory.

@juanlopez4691 get_test_theme_version() function introduce in version 5.2 that's why @davidbaumwald updated the version.

Added initial patch.

[mukesh27]

Initial patch.

[afragen]

Is the conditional in the patch the best way to test or would it be better as

property_exists( $active_theme, 'parent_theme' ) ? $active_theme->parent_theme : $active_theme->template;

[SergeyBiryukov]

It would be helpful to know the exact steps to reproduce the issue, as this code branch only runs if is_child_theme() is true, but WP_Theme::parent() only returns false if the current theme is not a child theme.

So it seems like the notice is only issued if the current theme is either broken or not properly configured.

Still, it seems like a good idea to avoid the PHP notice here, as the Themes screen should already give a proper error message for this case.

[SergeyBiryukov]

In 47815:

Site Health: Use WP_Theme::parent() in the inactive themes test as a more reliable check that the parent theme exists.

This is also more consistent with the other instances of directly referencing WP_Theme::parent() properties or methods in core.

Props mukesh27, juanlopez4691, davidbaumwald, afragen, SergeyBiryukov.
Fixes #49934.