From d9d7607622b21197a1134f07f88d67c993f55ade Mon Sep 17 00:00:00 2001
From: Nick Clemens <nick@bywatersolutions.com>
Date: Mon, 3 Dec 2018 13:05:49 +0000
Subject: [PATCH] Bug 21405 - Fix auhtorities pagination for Zebra and ES

Bug 20261 introduced an error because search_auth_compat responded
differently for ES and Zebra, now bug 19365 fixed the underlying
difference. This patch restores previous code to fix pagination.

Additionally we add a fix for 10000+ results in ES and remove a double
import of C4::Auth

To test:
 1 - Perform an authorities search with 1+ pages using Zebra
 2 - Page through results, note you are only offseeting by 1 each time
 3 - Perform an authorities search with 10,000+ results in ES
 4 - Click on the last page and get an error
 5 - Apply patch
 6 - Retry Zebra search
 7 - Results should paginate correctly
 8 - Clicking on last page should return last results
 9 - Retry ES results
10 - Results should paginate correct
11 - Clicking on last page should return last results
---
 authorities/authorities-home.pl | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/authorities/authorities-home.pl b/authorities/authorities-home.pl
index 3f400722c3..e0d5f754de 100755
--- a/authorities/authorities-home.pl
+++ b/authorities/authorities-home.pl
@@ -22,7 +22,7 @@ use warnings;
 
 use CGI qw ( -utf8 );
 use URI::Escape;
-use C4::Auth;
+use POSIX qw(ceil);
 
 use C4::Context;
 use C4::Auth;
@@ -86,6 +86,7 @@ if ( $op eq "do_search" ) {
 
     my $startfrom      = $query->param('startfrom')      || 1;
     my $resultsperpage = $query->param('resultsperpage') || 20;
+    my $offset = ( $startfrom - 1 ) * $resultsperpage + 1;
 
     my $builder = Koha::SearchEngine::QueryBuilder->new(
         { index => $Koha::SearchEngine::AUTHORITIES_INDEX } );
@@ -96,7 +97,7 @@ if ( $op eq "do_search" ) {
         [$value], $authtypecode, $orderby
     );
     my ( $results, $total ) = $searcher->search_auth_compat(
-        $search_query, $startfrom, $resultsperpage
+        $search_query, $offset, $resultsperpage
     );
 
     ( $template, $loggedinuser, $cookie ) = get_template_and_user(
@@ -180,6 +181,9 @@ if ( $op eq "do_search" ) {
 
     $template->param( result => $results ) if $results;
 
+    my $max_result_window = $searcher->max_result_window;
+    my $hits_to_paginate = ($max_result_window && $max_result_window < $total) ? $max_result_window : $total;
+
     $template->param(
         pagination_bar => pagination_bar(
             $base_url,  int( $total / $resultsperpage ) + 1,
-- 
2.11.0