Index: wp-admin/plugin-editor.php
===================================================================
--- wp-admin/plugin-editor.php	(revision 17592)
+++ wp-admin/plugin-editor.php	(working copy)
@@ -215,7 +215,7 @@
 		continue;
 	}
 ?>
-		<li<?php echo $file == $plugin_file ? ' class="highlight"' : ''; ?>><a href="plugin-editor.php?file=<?php echo $plugin_file; ?>&amp;plugin=<?php echo $plugin; ?>"><?php echo $plugin_file ?></a></li>
+		<li<?php echo $file == $plugin_file ? ' class="highlight"' : ''; ?>><a href="plugin-editor.php?file=<?php echo urlencode( $plugin_file ) ?>&amp;plugin=<?php echo urlencode( $plugin ) ?>"><?php echo $plugin_file ?></a></li>
 <?php endforeach; ?>
 	</ul>
 </div>
Index: wp-admin/theme-editor.php
===================================================================
--- wp-admin/theme-editor.php	(revision 17592)
+++ wp-admin/theme-editor.php	(working copy)
@@ -192,8 +192,8 @@
 	ksort( $template_mapping );
 	while ( list( $template_sorted_key, list( $template_file, $filedesc ) ) = each( $template_mapping ) ) :
 	?>
-		<li><a href="theme-editor.php?file=<?php echo "$template_file"; ?>&amp;theme=<?php echo urlencode($theme) ?>&amp;dir=theme"><?php echo $filedesc ?></a></li>
-<?php endwhile; ?>
+		<li><a href="theme-editor.php?file=<?php echo urlencode( $template_file ) ?>&amp;theme=<?php echo urlencode( $theme ) ?>&amp;dir=theme"><?php echo $filedesc ?></a></li>
+<?php endwhile; ?> 
 	</ul>
 	<h3><?php /* translators: Theme stylesheets in theme editor */ _ex('Styles', 'Theme stylesheets in theme editor'); ?></h3>
 	<ul>
@@ -214,7 +214,7 @@
 	ksort( $template_mapping );
 	while ( list( $template_sorted_key, list( $style_file, $filedesc ) ) = each( $template_mapping ) ) :
 		?>
-		<li><a href="theme-editor.php?file=<?php echo "$style_file"; ?>&amp;theme=<?php echo urlencode($theme) ?>&amp;dir=style"><?php echo $filedesc ?></a></li>
+		<li><a href="theme-editor.php?file=<?php echo urlencode( $style_file ) ?>&amp;theme=<?php echo urlencode($theme) ?>&amp;dir=style"><?php echo $filedesc ?></a></li>
 <?php endwhile; ?>
 	</ul>
 <?php endif; ?>