[34561] instituted the policy of forcing pagination for comments. This strategy
was intended to avert problems when 'page_comments' is set to 0 - as it is by
default - and the number of comments on a given post rises into the hundreds or
thousands. By forcing pagination in all cases, we ensured that WordPress would
not time out by processing unwieldy numbers of comments on a given pageload.
The strategy proves problematic, however, because comment permalinks are
generated using the page of the comment. Forcing pagination for posts that
were not previously paginated would change the URL of all comments that do not
appear on the default comment page.
This changeset reintroduces the 'page_comments' setting and its corresponding
checkbox on Settings > Discussion. A number of tests, which were written after
[34561], are modified to work now that 'page_comments' will, once again, be
disabled by default.
See #8071.
Built from https://develop.svn.wordpress.org/trunk@35331
git-svn-id: http://core.svn.wordpress.org/trunk@35297 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Previously, the 'page_comments' toggle allowed users to disable comment
pagination. This toggle was only superficial, however. Even with
'page_comments' turned on, `comments_template()` loaded all of a post's
comments into memory, and passed them to `wp_list_comments()` and
`Walker_Comment`, the latter of which produced markup for only the
current page of comments. In other words, it was possible to enable
'page_comments', thereby showing only a subset of a post's comments on a given
page, but all comments continued to be loaded in the background. This technique
scaled poorly. Posts with hundreds or thousands of comments would load slowly,
or not at all, even when the 'comments_per_page' setting was set to a
reasonable number.
Recent changesets have addressed this problem through more efficient tree-
walking, better descendant caching, and more selective queries for top-level
post comments. The current changeset completes the project by addressing the
root issue: that loading a post causes all of its comments to be loaded too.
Here's the breakdown:
* Comment pagination is now forced. Setting 'page_comments' to false leads to evil things when you have many comments. If you want to avoid pagination, set 'comments_per_page' to something high.
* The 'page_comments' setting has been expunged from options-discussion.php, and from places in the codebase where it was referenced. For plugins relying on 'page_comments', we now force the value to `true` with a `pre_option` filter.
* `comments_template()` now queries for an appropriately small number of comments. Usually, this means the `comments_per_page` value.
* To preserve the current (odd) behavior for comment pagination links, some unholy hacks have been inserted into `comments_template()`. The ugliness is insulated in this function for backward compatibility and to minimize collateral damage. A side-effect is that, for certain settings of 'default_comments_page', up to 2x the value of `comments_per_page` might be fetched at a time.
* In support of these changes, a `$format` parameter has been added to `WP_Comment::get_children()`. This param allows you to request a flattened array of comment children, suitable for feeding into `Walker_Comment`.
* `WP_Query` loops are now informed about total available comment counts and comment pages by the `WP_Comment_Query` (`found_comments`, `max_num_pages`), instead of by `Walker_Comment`.
Aside from radical performance improvements in the case of a post with many
comments, this changeset fixes a bug that caused the first page of comments to
be partial (`found_comments` % `comments_per_page`), rather than the last, as
you'd expect.
Props boonebgorges, wonderboymusic.
Fixes#8071.
Built from https://develop.svn.wordpress.org/trunk@34561
git-svn-id: http://core.svn.wordpress.org/trunk@34525 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Awesome rewrite bug: the `page` query var was being set to `'/4'` in `$wp`. When cast to `int`, it returns `0` (Bless you, PHP). `WP_Query` calls `trim( $page, '/' )` when setting its own query var. The few places that were checking `page` before posts were queried now have sanity checks, so that these changes work without flushing rewrites.
Adds/updates unit tests.
Props wonderboymusic, dd32.
See #11694.
Built from https://develop.svn.wordpress.org/trunk@34492
git-svn-id: http://core.svn.wordpress.org/trunk@34456 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Partial revert of r19737 and r19778 as some users were relying on this behaviour.
git-svn-id: http://core.svn.wordpress.org/trunk@21112 1a063a9b-81f0-0310-95a4-ce76da25c4cd
* Don't remove it on update. If you have it now, you'll keep it. New installs won't get it.
* Peform a redirect using rewrite + canonical to the new location, if the file doesn't exist.
props SergeyBiryukov.
fixes#18544.
git-svn-id: http://svn.automattic.com/wordpress/trunk@20596 1a063a9b-81f0-0310-95a4-ce76da25c4cd
