In `get_network_by_path()`, `$exact_domains` is unused.

See #27882.


git-svn-id: https://develop.svn.wordpress.org/trunk@28329 602fd350-edb4-49c9-b593-d223f7449a82
In `Walker_Nav_Menu::start_el()`, `$class_names` is set twice before it is used.

See #27882.


git-svn-id: https://develop.svn.wordpress.org/trunk@28330 602fd350-edb4-49c9-b593-d223f7449a82
In `wp_get_attachment_link()`, `$post_title` is set and then not used.

See #27882.


git-svn-id: https://develop.svn.wordpress.org/trunk@28331 602fd350-edb4-49c9-b593-d223f7449a82
In `get_pages()`, `$cache` does not need to be reset to an empty array. `update_post_cache( $pages )` takes care of priming.

In `set_post_thumbnail()`, (accidental) assignment is unnecessary for `$thumbnail_html` as it is not used. 

See #27882.


git-svn-id: https://develop.svn.wordpress.org/trunk@28332 602fd350-edb4-49c9-b593-d223f7449a82