WP Super Cache doesn’t cache 404s… should it?

Hi,

Just wondering what the thinking behind WP Super Cache not caching 404 responses is? I can see no generic disadvantage to it doing so, although I suppose some themes might provide “helpful” dynamically generated 404 error pages. Perhaps a filter or option to allow caching of 404s might be handy?

Here’s a patch I made to WPSC to allow caching of 404 requests:

Index: /Users/simon/Projects/SF/trunk/site/wp-content/plugins/wp-super-cache/wp-cache-phase2.php
===================================================================
--- /Users/simon/Projects/SF/trunk/site/wp-content/plugins/wp-super-cache/wp-cache-phase2.php	(revision 2566)
+++ /Users/simon/Projects/SF/trunk/site/wp-content/plugins/wp-super-cache/wp-cache-phase2.php	(working copy)
@@ -251,7 +251,7 @@

 	/* Mode paranoic, check for closing tags
 	 * we avoid caching incomplete files */
-	if( $wp_cache_404 ) {
+	if( $wp_cache_404 && !apply_filters( 'supercache_404s', true ) ) {
 		$new_cache = false;
 		$buffer .= "\n<!-- Page not cached by WP Super Cache. 404. -->\n";
 	}

S