Index: wp-includes/template-loader.php
===================================================================
--- wp-includes/template-loader.php	(revision 13200)
+++ wp-includes/template-loader.php	(working copy)
@@ -1,78 +1,53 @@
 <?php
 /**
- * Loads the correct template based on the visitor's url
+ * Loads the correct template based on the url requested.
+ *
  * @package WordPress
  */
-if ( defined('WP_USE_THEMES') && constant('WP_USE_THEMES') ) {
-	do_action('template_redirect');
-	if ( is_robots() ) {
-		do_action('do_robots');
-		return;
-	} else if ( is_feed() ) {
-		do_feed();
-		return;
-	} else if ( is_trackback() ) {
-		include(ABSPATH . 'wp-trackback.php');
-		return;
-	} else if ( is_404() && $template = get_404_template() ) {
-		include($template);
-		return;
-	} else if ( is_search() && $template = get_search_template() ) {
-		include($template);
-		return;
-	} else if ( is_tax() && $template = get_taxonomy_template()) {
-		include($template);
-		return;
-	} else if ( is_home() && $template = get_home_template() ) {
-		include($template);
-		return;
-	} else if ( is_attachment() && $template = get_attachment_template() ) {
+
+if ( $flag_themes = ( defined( 'WP_USE_THEMES' ) && constant( 'WP_USE_THEMES' ) ) ) 
+	do_action( 'template_redirect' );
+
+/* Default actions regardless of wether themes are used or not */
+if ( is_robots() ) {
+	do_action( 'do_robots' );
+	return;
+} else if ( is_feed() ) {
+	do_feed();
+	return;
+} else if ( is_trackback() ) {
+	include( ABSPATH . 'wp-trackback.php' );
+	return;
+}
+
+/* Load the template if themes are used */
+if ( $flag_themes ) {
+	if ( is_404()            	 && $template = get_404_template()            ) :
+	elseif ( is_search()         && $template = get_search_template()         ) :
+	elseif ( is_tax()            && $template = get_taxonomy_template()       ) :
+	elseif ( is_home()           && $template = get_home_template()           ) :
+	elseif ( is_attachment()     && $template = get_attachment_template()     ) :
 		remove_filter('the_content', 'prepend_attachment');
-		include($template);
-		return;
-	} else if ( is_single() && $template = get_single_template() ) {
-		include($template);
-		return;
-	} else if ( is_page() && $template = get_page_template() ) {
-		include($template);
-		return;
-	} else if ( is_category() && $template = get_category_template()) {
-		include($template);
-		return;
-	} else if ( is_tag() && $template = get_tag_template()) {
-		include($template);
-		return;
-	} else if ( is_author() && $template = get_author_template() ) {
-		include($template);
-		return;
-	} else if ( is_date() && $template = get_date_template() ) {
-		include($template);
-		return;
-	} else if ( is_archive() && $template = get_archive_template() ) {
-		include($template);
-		return;
-	} else if ( is_comments_popup() && $template = get_comments_popup_template() ) {
-		include($template);
-		return;
-	} else if ( is_paged() && $template = get_paged_template() ) {
-		include($template);
-		return;
-	} else if ( file_exists(TEMPLATEPATH . "/index.php") ) {
-		include(TEMPLATEPATH . "/index.php");
-		return;
-	}
-} else {
-	// Process feeds and trackbacks even if not using themes.
-	if ( is_robots() ) {
-		do_action('do_robots');
-		return;
-	} else if ( is_feed() ) {
-		do_feed();
-		return;
-	} else if ( is_trackback() ) {
-		include(ABSPATH . 'wp-trackback.php');
-		return;
-	}
+	elseif ( is_single()         && $template = get_single_template()         ) :
+	elseif ( is_page()           && $template = get_page_template()           ) :
+	elseif ( is_category()       && $template = get_category_template()       ) :
+	elseif ( is_tag()            && $template = get_tag_template()            ) :
+	elseif ( is_author()         && $template = get_author_template()         ) :
+	elseif ( is_date()           && $template = get_date_template()           ) :
+	elseif ( is_archive()        && $template = get_archive_template()        ) :
+	elseif ( is_comments_popup() && $template = get_comments_popup_template() ) :
+	elseif ( is_paged()          && $template = get_paged_template()          ) :
+	elseif ( file_exists(TEMPLATEPATH . '/index.php') ) :
+		$template = TEMPLATEPATH . '/index.php';
+	endif;
 }
 
+unset( $flag_themes );
+
+if ( $template = apply_filters('template_include', $template) ) {
+	include( $template );
+	do_action( 'template_loaded', $template );
+	return;
+}
+
 ?>
\ No newline at end of file