Index: openacs-4/packages/wp-slim/www/display-change.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/wp-slim/www/display-change.tcl,v
diff -u -r1.7 -r1.8
--- openacs-4/packages/wp-slim/www/display-change.tcl	12 Sep 2013 20:47:19 -0000	1.7
+++ openacs-4/packages/wp-slim/www/display-change.tcl	27 Jun 2015 20:34:41 -0000	1.8
@@ -28,13 +28,13 @@
     where revision_id = :revision_id
 }]
 
-if { ![empty_string_p $display] } {
-    if { [cr_registered_type_for_mime_type $mime_type] != "image" } {
+if { $display ne "" } {
+    if { [cr_registered_type_for_mime_type $mime_type] ne "image" } {
 	ad_return_complaint 1 "<li>[_ wp-slim.lt_The_file_is_neither_a]"
         ad_script_abort
     }
     db_dml display_change ""
 }
 
 
-ad_returnredirect "attach-detail?[export_vars -url {slide_item_id attach_item_id file_name}]"
+ad_returnredirect [export_vars -base attach-detail {slide_item_id attach_item_id file_name}]