id,summary,reporter,owner,description,type,status,priority,milestone,component,version,severity,resolution,keywords,cc
19275,Rewrite endpoints don't work with taxonomies,sillybean,nacin,"Adding a rewrite endpoint on category archives apparently confuses WP_Query and results in 404 errors. That is, according to all the documentation I have found on WP-Rewrite, this should work:

http://example.com/category/slug/format/myformat/

But instead, you have to use:

http://example.com/category/slug/?format=myformat

Excerpt from a sample plugin:

{{{
#!php
// Add permalink structure, flush rules on activation/deactivation
function uwc_ebook_activate() {
	uwc_ebook_add_rewrites();
	flush_rewrite_rules();
}
function uwc_ebook_deactivate() {
	flush_rewrite_rules();
}
register_activation_hook(__FILE__, 'uwc_ebook_activate');
register_deactivation_hook(__FILE__, 'uwc_ebook_deactivate');

// Add rewrite endpoint
function uwc_ebook_add_rewrites() {
	add_rewrite_endpoint('format', EP_CATEGORIES);
	// this doesn't work either:
	// add_rewrite_endpoint('format', EP_ALL);
}
add_filter('init', 'uwc_ebook_add_rewrites');

// Handle the endpoint display
function uwc_ebook_template_redirect() {
//	global $wp_query; var_dump($wp_query); exit;
	$format = get_query_var('format');
	$cat = get_query_var('cat');
	if ($format == 'epub' && isset($cat)) {
		$category = get_category($cat);
		if (!is_wp_error($category)) {
			$uploads = wp_upload_dir();
			$ebookurl = $uploads['baseurl'].'/ebooks/'.$category->slug.'/'.$category->slug.'.epub';
			wp_redirect( $ebookurl, 301 );
			exit;
		}
	} 
}
add_filter('template_redirect', 'uwc_ebook_template_redirect');

// the rest of the plugin generates the epub file containing all posts in that category
}}}

Uncommenting the $wp_query line shows what's going on. Relevant parts of the var dump, from the Science & Technical subcategory of How-To:

{{{
#!php
[""category_name""]=>
    string(4) ""epub""
[""query""]=>
  array(1) {
    [""category_name""]=>
    string(36) ""how-to/science-technical/format/epub""
  }
}}}

Using /how-to/science-technical/?format=epub instead, WP correctly recognizes the category and format as two different query vars.

I tested this in the latest nightly build, and it's broken there as well.

Bill Erickson had a similar problem a few weeks ago, in which he used EP_ALL and found that it worked everywhere except category archives:
https://gist.github.com/1287996",defect (bug),closed,normal,3.4,Permalinks,3.1,normal,fixed,has-patch,bill.erickson@… gabriel.koen@… ben@… dempsey@… marko@…