Save both template and stylesheet.

This way we don't have to instantiate WP_Theme on every page request.

-/php/config.php

@@ -450,9 +450,10 @@ public function collection_theme() {
 			<?php
 				foreach ( wp_get_themes() as $theme ) {
 					printf(
-						'<option value="%s"%s>%s</option>',
+						'<option value="%s|%s"%s>%s</option>',
+						$theme[ 'Template' ],
 						$theme[ 'Stylesheet' ],
-						selected( $theme[ 'Stylesheet' ], self::$config[ 'collections' ][ $_GET[ 'post_type' ] ][ 'theme' ], false ),
+						selected( $theme[ 'Template' ] . '|' . $theme[ 'Stylesheet' ], self::$config[ 'collections' ][ $_GET[ 'post_type' ] ][ 'theme' ], false ),
 						esc_html( $theme[ 'Name' ] )
 					);
 				}

webcomic.php

@@ -575,11 +575,7 @@ public function template_redirect() {
 	 * @hook template
 	 */
 	public function template( $theme ) {
-		if ( self::$collection and self::$config[ 'collections' ][ self::$collection ][ 'theme' ] ) {
-			return ( $child = new WP_Theme( get_stylesheet_directory(), '' ) and $child->get( 'Template' ) ) ? $child->get( 'Template' ) : self::$config[ 'collections' ][ self::$collection ][ 'theme' ];
-		}
-
-		return $theme;
+		return ( self::$collection and self::$config[ 'collections' ][ self::$collection ][ 'theme' ] ) ? substr( self::$config[ 'collections' ][ self::$collection ][ 'theme' ], 0, strpos( self::$config[ 'collections' ][ self::$collection ][ 'theme' ], '|' ) ) : $theme;
 	}
 
 	/** Return the appropriate theme ID for custom collection themes.
@@ -591,7 +587,7 @@ public function template( $theme ) {
 	 * @hook stylesheet
 	 */
 	public function stylesheet( $theme ) {
-		return ( self::$collection and self::$config[ 'collections' ][ self::$collection ][ 'theme' ] ) ? self::$config[ 'collections' ][ self::$collection ][ 'theme' ] : $theme;
+		return ( self::$collection and self::$config[ 'collections' ][ self::$collection ][ 'theme' ] ) ? substr( self::$config[ 'collections' ][ self::$collection ][ 'theme' ], strpos( self::$config[ 'collections' ][ self::$collection ][ 'theme' ], '|' ) + 1 ) : $theme;
 	}
 
 	/** Integrate webcomics into the main site feed.