Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.756.2.73
diff -u -p -r1.756.2.73 common.inc
--- includes/common.inc	6 Nov 2009 08:34:58 -0000	1.756.2.73
+++ includes/common.inc	25 Nov 2009 04:20:29 -0000
@@ -1523,7 +1523,17 @@ function drupal_attributes($attributes =
   if (is_array($attributes)) {
     $t = '';
     foreach ($attributes as $key => $value) {
-      $t .= " $key=".'"'. check_plain($value) .'"';
+      // Implode arrays.
+      if (is_array($value)) {
+        $value = implode(' ', $value);
+      }
+      // Empty values just get sent back.
+      if (empty($value)) {
+        $t .= " $key=".'""';
+      }
+      else {
+        $t .= " $key=".'"'. check_plain($value) .'"';
+      }
     }
     return $t;
   }