Index: openacs-4/packages/xowiki/tcl/xowiki-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xowiki/tcl/xowiki-procs.tcl,v
diff -u -N -r1.542.2.7 -r1.542.2.8
--- openacs-4/packages/xowiki/tcl/xowiki-procs.tcl	29 Mar 2019 11:26:41 -0000	1.542.2.7
+++ openacs-4/packages/xowiki/tcl/xowiki-procs.tcl	1 Apr 2019 15:21:26 -0000	1.542.2.8
@@ -1266,6 +1266,20 @@
   Page instforward form_parameter {%set :package_id} %proc
   Page instforward exists_form_parameter {%set :package_id} %proc
 
+  Page insproc get_query_parameter_return_url {{default ""}} {
+    #
+    # Get the return_url from query parameters and check, if this is
+    # local.
+    #
+    set return_url [:query_parameter "return_url" $default]
+    if {[util::external_url $return_url]} {
+      ad_return_complaint 1 "Page <b>'${:name}'</b> non-local return_url was specified"
+      ad_script_abort
+    }
+    return $return_url
+  }
+
+
   #   Page instproc init {} {
   #     :log "--W "
   #     ::xo::show_stack