Index: openacs-4/packages/file-storage/www/simple-add.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/file-storage/www/simple-add.tcl,v
diff -u -r1.17 -r1.17.2.1
--- openacs-4/packages/file-storage/www/simple-add.tcl	19 Jan 2018 12:03:41 -0000	1.17
+++ openacs-4/packages/file-storage/www/simple-add.tcl	17 Apr 2019 19:16:00 -0000	1.17.2.1
@@ -64,8 +64,14 @@
 ad_form -extend -form {
     {url:text(text) {label \#file-storage.URL\#} {value "http://"}}
     {description:text(textarea),optional {html {rows 5 cols 50}} {label \#file-storage.Description\#}}
+} -validate {
+    {url
+        {[string match "data:*" [string trim $url]] == 0}
+        "\$url\" must not start with 'data:'"
+    }
 }
 
+
 set package_id [ad_conn package_id]
 set user_id [ad_conn user_id]
 if { [parameter::get -parameter CategoriesP -package_id $package_id -default 0] } {