--- loncom/interface/loncommon.pm	2016/07/08 17:21:01	1.1249
+++ loncom/interface/loncommon.pm	2016/07/18 19:28:58	1.1250
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # a pile of common routines
 #
-# $Id: loncommon.pm,v 1.1249 2016/07/08 17:21:01 damieng Exp $
+# $Id: loncommon.pm,v 1.1250 2016/07/18 19:28:58 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -10625,7 +10625,9 @@ reservable_now - ref to hash of student_
 
     Keys in inner hash are:
     (a) symb: either blank or symb to which slot use is restricted.
-    (b) endreserve: end date of reservation period. 
+    (b) endreserve: end date of reservation period.
+    (c) uniqueperiod: start,end dates when slot is to be uniquely
+        selected.
 
 sorted_future - ref to array of student_schedulable slots reservable in
                 the future, ordered by start date of reservation period.
@@ -10635,7 +10637,9 @@ future_reservable - ref to hash of stude
 
     Keys in inner hash are:
     (a) symb: either blank or symb to which slot use is restricted.
-    (b) startreserve:  start date of reservation period.
+    (b) startreserve: start date of reservation period.
+    (c) uniqueperiod: start,end dates when slot is to be uniquely
+        selected.
 
 =back
 
@@ -10711,6 +10715,10 @@ sub get_future_slots {
             my $startreserve = $slots{$slot}->{'startreserve'};
             my $endreserve = $slots{$slot}->{'endreserve'};
             my $symb = $slots{$slot}->{'symb'};
+            my $uniqueperiod;
+            if (ref($slots{$slot}->{'uniqueperiod'}) eq 'ARRAY') {
+                $uniqueperiod = join(',',@{$slots{$slot}->{'uniqueperiod'}});
+            }
             if (($startreserve < $now) &&
                 (!$endreserve || $endreserve > $now)) {
                 my $lastres = $endreserve;
@@ -10719,13 +10727,15 @@ sub get_future_slots {
                 }
                 $reservable_now{$slot} = {
                                            symb       => $symb,
-                                           endreserve => $lastres
+                                           endreserve => $lastres,
+                                           uniqueperiod => $uniqueperiod,
                                          };
             } elsif (($startreserve > $now) &&
                      (!$endreserve || $endreserve > $startreserve)) {
                 $future_reservable{$slot} = {
                                               symb         => $symb,
-                                              startreserve => $startreserve
+                                              startreserve => $startreserve,
+                                              uniqueperiod => $uniqueperiod,
                                             };
             }
         }