Index: openacs-4/packages/acs-subsite/lib/user-new.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-subsite/lib/user-new.tcl,v
diff -u -r1.18 -r1.18.4.1
--- openacs-4/packages/acs-subsite/lib/user-new.tcl	10 Feb 2011 15:17:01 -0000	1.18
+++ openacs-4/packages/acs-subsite/lib/user-new.tcl	5 Oct 2013 13:02:11 -0000	1.18.4.1
@@ -21,7 +21,7 @@
     return_url {}
 }
 foreach parameter [array names parameter_defaults] { 
-    if { ![exists_and_not_null $parameter] } { 
+    if { (![info exists $parameter] || $$parameter eq "") } { 
         set $parameter $parameter_defaults($parameter)
     }
 }
@@ -60,7 +60,7 @@
     }
 }
 
-if { [exists_and_not_null rel_group_id] } {
+if { ([info exists rel_group_id] && $rel_group_id ne "") } {
     ad_form -extend -name register -form {
         {rel_group_id:integer(hidden),optional}
     }
@@ -101,7 +101,7 @@
                                      -secret_question $secret_question \
                                      -secret_answer $secret_answer]
 	
-        if { $creation_info(creation_status) eq "ok" && [exists_and_not_null rel_group_id] } {
+        if { $creation_info(creation_status) eq "ok" && ([info exists rel_group_id] && $rel_group_id ne "") } {
             group::add_member \
                 -group_id $rel_group_id \
                 -user_id $user_id \
@@ -158,7 +158,7 @@
     
     
     # User is registered and logged in
-    if { ![exists_and_not_null return_url] } {
+    if { (![info exists return_url] || $return_url eq "") } {
         # Redirect to subsite home page.
         set return_url [subsite::get_element -element url]
     }