Fixes bug where an invalid Last-Modified value would be returned in feed requests for sites that had 0 items to return. Comment or post feeds will now return the current timestamp as the Last-Modified header value. Example: a request for the comments feed for a site without any comments.
Replaced use of the local static variable `$cache_lastcommentmodified` to store the modified date in `get_lastcommentmodified()` with the Object Cache API. The `get_lastcommentmodified()` function returns early if there is a cached value and returns `false` if there where no comments found. Introduced `_clear_modified_cache_on_transition_comment_status()` to flush the `lastcommentmodified` cache key when a comment enters or leaves approval status. In `get_lastpostmodified()` return early if there is a cached value and return `false` if there are no posts found.
Props swissspidy, rachelbaker, dllh, leobaiano.
Fixes#38027.
Built from https://develop.svn.wordpress.org/trunk@38925
git-svn-id: http://core.svn.wordpress.org/trunk@38868 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Introduces more flexibility in filtering all parts of the document title,the
separator, and a way to short-circuit title generation. Plugins can now also
check for theme support and reliably filter the entire output. See #18548.
Deprecates `wp_title()`.
Fixes#31078.
Built from https://develop.svn.wordpress.org/trunk@35294
git-svn-id: http://core.svn.wordpress.org/trunk@35260 1a063a9b-81f0-0310-95a4-ce76da25c4cd
These commits were accidentally re-synced commits from develop.svn.wordpress.org due to a race condition. Thankfully, the history of this repository matters fairly little. It also happened only for trunk.
git-svn-id: http://core.svn.wordpress.org/trunk@25876 1a063a9b-81f0-0310-95a4-ce76da25c4cd
