Ticket #6481: 6481.16.diff

wp-admin/includes/upgrade.php

@@ -264 +264 @@
 
 if ( ! function_exists( 'wp_install_maybe_enable_pretty_permalinks' ) ) :
 /**
- * Enable pretty permalinks if available.
+ * Enable pretty permalinks.
  *
- * This function will enable pretty permalinks if it can verify they work.
- * If all pretty permalinks formats fail to work, WordPress will fall back
- * to ugly permalinks by setting an empty permalink structure.
+ * If after enabling pretty permalinks don't work, fallback to query-string permalinks.
  *
  * @since 4.2.0
  *
@@ -277 +275 @@
 function wp_install_maybe_enable_pretty_permalinks() {
         global $wp_rewrite;
 
-        // Bail if we alredy have permalinks enabled (Multisite)
+        // Bail if a permalink structure is already enabled.
         if ( get_option( 'permalink_structure' ) ) {
                 return;
         }
 
         /*
-         * The Permalink structures which WordPress should attempt to use.
+         * The Permalink structures to attempt.
+         *
          * The first is designed for mod_rewrite or nginx rewriting.
-         * The second is PATHINFO based permalinks offered under configurations 
-         * without rewrites enabled.
+         *
+         * The second is PATHINFO-based permalinks for web server configurations
+         * without a true rewrite module enabled.
          */
         $permalink_structures = array(
                 '/%year%/%monthnum%/%day%/%postname%/',
@@ -294 +294 @@
         );
 
         foreach ( (array) $permalink_structures as $permalink_structure ) {
-                // Set the desired Permalink structure to try
                 $wp_rewrite->set_permalink_structure( $permalink_structure );
 
                 /*
@@ -303 +302 @@
                  */
                 $wp_rewrite->flush_rules( true );
 
-                // Test against a real WordPress Post, or if none were created, a Page URI
+                // Test against a real WordPress Post, or if none were created, a random 404 page.
                 $test_url = get_permalink( 1 );
                 if ( ! $test_url ) {
                         $test_url = home_url( '/wordpress-check-for-rewrites/' );
                 }
 
                 /*
-                 * Send a HEAD request to a random page on the site, and check whether
+                 * Send a request to the site, and check whether
                  * the 'x-pingback' header is returned as expected.
+                 *
+                 * Uses wp_remote_get() instead of wp_remote_head() because web servers
+                 * can block head requests.
                  */
                 $response          = wp_remote_get( $test_url, array( 'timeout' => 5 ) );
                 $x_pingback_header = wp_remote_retrieve_header( $response, 'x-pingback' );
@@ -323 +325 @@
         }
 
         /*
-         * If it makes it this far, Pretty Permalinks failed to activate.
-         * Reset and allow the user to select it themselves.
+         * If it makes it this far, pretty permalinks failed.
+         * Fallback to query-string permalinks.
          */
         $wp_rewrite->set_permalink_structure( '' );
         $wp_rewrite->flush_rules( true );