The "site_icon" option isn't always removed when the site icon is deleted

[henry.wright]

If you delete the site icon image by going to Media > Library, the "site_icon" option isn't deleted from the database. Note the option is deleted if you go Appearance > Customize and remove the icon through the Site Identity tab.

[henry.wright]

I should clarify.

When the site icon is removed by Appearance > Customize, the value of site_icon in the options table is either set to 0 or the option is deleted.

When the site icon image file is deleted by Media > Library, the value of site_icon in the options table remains something like 55.

This causes problems because the result of get_option( 'site_option' ) is used to determine if a site icon exists in functions like get_site_icon_url().

$site_icon_id = get_option( 'site_icon' );
 
if ( $site_icon_id ) {
    // This does not guarantee the site icon exists because of the bug above
}

[henry.wright]

49086.diff deletes the site_icon option if the media file used for the site icon is deleted.

[r-a-y]

I can confirm this bug. If a site icon is manually deleted from the Media Library, the corresponding site_icon option is never updated or removed.

Although a developer can use has_site_icon() to determine the existence of a site icon, some might use get_option( 'blog_icon' ) directly as @henry.wright mentions.