diff --git a/wp-includes/bookmark-template.php b/wp-includes/bookmark-template.php
index 68a2842cf..70e495ce0 100644
--- a/wp-includes/bookmark-template.php
+++ b/wp-includes/bookmark-template.php
@@ -4,12 +4,15 @@ function _walk_bookmarks($bookmarks, $args = '' ) {
 	$defaults = array(
 		'show_updated' => 0, 'show_description' => 0,
 		'show_images' => 1, 'before' => '<li>',
-		'after' => '</li>', 'between' => "\n"
+		'after' => '</li>', 'between' => "\n",
+		'show_rating' => 0
 	);
 
 	$r = wp_parse_args( $args, $defaults );
 	extract( $r, EXTR_SKIP );
 
+	$output = ''; // Blank string to start with.
+	
 	foreach ( (array) $bookmarks as $bookmark ) {
 		if ( !isset($bookmark->recently_updated) )
 			$bookmark->recently_updated = false;
diff --git a/wp-includes/canonical.php b/wp-includes/canonical.php
index 1d95b22ad..063d8b546 100644
--- a/wp-includes/canonical.php
+++ b/wp-includes/canonical.php
@@ -20,7 +20,7 @@ function redirect_canonical($requested_url=NULL, $do_redirect=true) {
 
 	// Some PHP setups turn requests for / into /index.php in REQUEST_URI
 	$original['path'] = preg_replace('|/index\.php$|', '/', $original['path']);
-
+	
 	$redirect = $original;
 	$redirect_url = false;
 
diff --git a/wp-includes/classes.php b/wp-includes/classes.php
index 4002930d0..b5ba180ca 100644
--- a/wp-includes/classes.php
+++ b/wp-includes/classes.php
@@ -527,6 +527,9 @@ class Walker_Page extends Walker {
 	function start_el($output, $page, $depth, $current_page, $args) {
 		if ( $depth )
 			$indent = str_repeat("\t", $depth);
+		else
+			$indent = '';
+			
 		extract($args, EXTR_SKIP);
 		$css_class = 'page_item page-item-'.$page->ID;
 		$_current_page = get_page( $current_page );
@@ -646,15 +649,15 @@ class Walker_Category extends Walker {
 			$link .= ' ' . gmdate('Y-m-d', $category->last_update_timestamp);
 		}
 
-		if ( $current_category )
+		if ( isset($current_category) && $current_category )
 			$_current_category = get_category( $current_category );
 
 		if ( 'list' == $args['style'] ) {
 			$output .= "\t<li";
 			$class = 'cat-item cat-item-'.$category->term_id;
-			if ( $current_category && ($category->term_id == $current_category) )
+			if ( isset($current_category) && $current_category && ($category->term_id == $current_category) )
 				$class .=  ' current-cat';
-			elseif ( $_current_category && ($category->term_id == $_current_category->parent) )
+			elseif ( isset($_current_category) && $_current_category && ($category->term_id == $_current_category->parent) )
 				$class .=  ' current-cat-parent';
 			$output .=  ' class="'.$class.'"';
 			$output .= ">$link\n";
diff --git a/wp-includes/widgets.php b/wp-includes/widgets.php
index a6a5aa068..124af8176 100644
--- a/wp-includes/widgets.php
+++ b/wp-includes/widgets.php
@@ -203,7 +203,7 @@ function dynamic_sidebar($index = 1) {
 
 	$sidebars_widgets = wp_get_sidebars_widgets();
 
-	if ( empty($wp_registered_sidebars[$index]) || !is_array($sidebars_widgets[$index]) || empty($sidebars_widgets[$index]) )
+	if ( empty($wp_registered_sidebars[$index]) || !array_key_exists($index, $sidebars_widgets) || !is_array($sidebars_widgets[$index]) || empty($sidebars_widgets[$index]) )
 		return false;
 
 	$sidebar = $wp_registered_sidebars[$index];