MDL-26153 fix yui combo loading for images with numbers in file name

theme/yui_combo.php

@@ -93,18 +93,18 @@
 
     if ($mimetype === 'text/css') {
         if ($version == 'moodle') {
-            $filecontent = preg_replace('/([a-z_-]+)\.(png|gif)/', 'yui_image.php?file='.$version.'/'.$frankenstyle.'/'.array_shift($bits).'/$1.$2', $filecontent);
+            $filecontent = preg_replace('/([a-z0-9_-]+)\.(png|gif)/', 'yui_image.php?file='.$version.'/'.$frankenstyle.'/'.array_shift($bits).'/$1.$2', $filecontent);
         } else if ($version == 'gallery') {
             // search for all images in gallery module CSS and serve them through the yui_image.php script
-            $filecontent = preg_replace('/([a-z_-]+)\.(png|gif)/', 'yui_image.php?file='.$version.'/'.$bits[0].'/'.$bits[1].'/$1.$2', $filecontent);
+            $filecontent = preg_replace('/([a-z0-9_-]+)\.(png|gif)/', 'yui_image.php?file='.$version.'/'.$bits[0].'/'.$bits[1].'/$1.$2', $filecontent);
         } else {
             // First we need to remove relative paths to images. These are used by YUI modules to make use of global assets.
             // I've added this as a separate regex so it can be easily removed once
             // YUI standardise there CSS methods
-            $filecontent = preg_replace('#(\.\./\.\./\.\./\.\./assets/skins/sam/)?([a-z_-]+)\.(png|gif)#', '$2.$3', $filecontent);
+            $filecontent = preg_replace('#(\.\./\.\./\.\./\.\./assets/skins/sam/)?([a-z0-9_-]+)\.(png|gif)#', '$2.$3', $filecontent);
 
             // search for all images in yui2 CSS and serve them through the yui_image.php script
-            $filecontent = preg_replace('/([a-z_-]+)\.(png|gif)/', 'yui_image.php?file='.$version.'/$1.$2', $filecontent);
+            $filecontent = preg_replace('/([a-z0-9_-]+)\.(png|gif)/', 'yui_image.php?file='.$version.'/$1.$2', $filecontent);
         }
     }