Index: openacs-4/packages/search/www/search.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/search/www/search.tcl,v
diff -u -N -r1.40.2.5 -r1.40.2.6
--- openacs-4/packages/search/www/search.tcl	24 May 2016 22:01:15 -0000	1.40.2.5
+++ openacs-4/packages/search/www/search.tcl	28 May 2016 09:49:31 -0000	1.40.2.6
@@ -7,8 +7,8 @@
     {t:trim ""}
     {offset:naturalnum,notnull 0}
     {num:range(0|200) 0}
-    {dfs:word,trim ""}
-    {dts:word,trim ""}
+    {dfs:word,trim,notnull ""}
+    {dts:word,trim,notnull ""}
     {search_package_id:naturalnum ""}
     {scope ""}
     {object_type:token ""}
@@ -18,6 +18,23 @@
             ad_complain "#search.lt_You_must_specify_some#"
         }
     }
+    valid_dfs -requires dfs {
+        if {![array exists symbol2interval]} {
+            array set symbol2interval [parameter::get -package_id [ad_conn package_id] -parameter Symbol2Interval]
+        }
+        if {$dfs ni [array names symbol2interval]} {
+            ad_complain "dfs: invalid interval"
+        }
+    }
+    valid_dts -requires dts {
+        if {![array exists symbol2interval]} {
+            array set symbol2interval [parameter::get -package_id [ad_conn package_id] -parameter Symbol2Interval]
+        }
+        if {$dts ni [array names symbol2interval]} {
+            ad_complain "dts: invalid interval"
+        }
+    }
+    
     csrf { security::csrf::validate }
 }
 
@@ -64,7 +81,6 @@
     set dfs ""
 }
 
-array set symbol2interval [parameter::get -package_id $package_id -parameter Symbol2Interval]
 if { $dfs ne "" } {
     set df [db_exec_plsql get_df "select now() + '$symbol2interval($dfs)'::interval"]
 }