Index: openacs-4/packages/file-storage/www/file-add.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/file-storage/www/file-add.tcl,v
diff -u -N -r1.28.2.2 -r1.28.2.3
--- openacs-4/packages/file-storage/www/file-add.tcl	31 Mar 2021 11:32:54 -0000	1.28.2.2
+++ openacs-4/packages/file-storage/www/file-add.tcl	7 Jun 2021 14:00:06 -0000	1.28.2.3
@@ -233,6 +233,13 @@
             set upload_file $name
         }
 
+        # The upload filename is the one we are going to use as
+        # download filename. Must be safe.
+        set upload_file [ad_sanitize_filename \
+                             -collapse_spaces \
+                             -tolower \
+                             $upload_file]
+
         set existing_item_id [fs::get_item_id -name $upload_file -folder_id $folder_id]
 
         if {$existing_item_id ne ""} {