Menus adds "current_page_parent" class to the blog page when viewing a custom post type entry

[tammyhart]

Here is an example: ​http://www.flowermag.com/article/love-rocks/

This entry is in the custom post type "article", but the navigation item "blog" is getting the class "current_page_parent" even though an article is not a blog post.

This is a problem since if you're using "current_page_parent" for navigation highlighting, this would render an incorrect display.

[filosofo]

current_page_parent is meant to make the menus work in a backwards-compatible way with the classes given to pages in lists, thanks to Walker_Page.

Specifically, Walker_Page, which generates the class names for many page lists, considers everything not a page to be a child of the "posts page." Maybe it shouldn't, but that's the behavior that would need to be changed first.

Instead, you can use the "current-menu-parent" class to specify elements that are parents of the currently-requested page, without this backwards-compatibility quirk.