Bug 10553: make public lists available on OPAC login page

If you are not logged in to the OPAC, looking at the login page, and you
click the Lists button to see public lists it says there are none. This
patch corrects Auth.pm so that it loads the list of public lists in this
situation.

To test you must have at least one public list. Make sure you are logged
out of the OPAC and visit the login page (/cgi-bin/koha/opac-user.pl).
Clicking the "Lists" button should show you a list of public shelves.

Signed-off-by: Liz Rea <liz@catalyst.net.nz>
works as described, and list button is not shown when opacpublic is disabled.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit 651f810f68)
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>
(cherry picked from commit c7e19ee643)
Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
(cherry picked from commit c7e19ee643)

C4/Auth.pm

@@ -993,6 +993,14 @@ sub checkauth {
     $template->param( OpacPublic => C4::Context->preference("OpacPublic"));
     $template->param( loginprompt => 1 ) unless $info{'nopermission'};
 
+    if($type eq 'opac'){
+        my ($total, $pubshelves) = C4::VirtualShelves::GetSomeShelfNames(undef, 'MASTHEAD');
+        $template->param(
+            pubshelves     => $total->{pubtotal},
+            pubshelvesloop => $pubshelves,
+        );
+    }
+
     if ($cas) {
 
 	# Is authentication against multiple CAS servers enabled?