From 263c00ba5cb317c48128984ce7c4a691450155c8 Mon Sep 17 00:00:00 2001
From: Fridolin Somers <fridolin.somers@biblibre.com>
Date: Wed, 7 Feb 2018 15:06:56 +0100
Subject: [PATCH] Bug 20151: always use current language for stemming

When stemming is enabled, in catalog searching "C4::Search::_build_stemmed_operand" will transform query operand into stemmed operand using stemmer Lingua::Stem::Snowball with a specified language.
This stemmer returns undef stemmed operand if no language is defined.

In main catalog search (catalogue/search.pl) current language is used.
But in other pages "acqui/neworderbiblio.pl" and "cataloguing/addbooks.pl" no language is defined so stemmed operand is empty and so stemming is not applied.

This patch corrects by returning in "C4::Search::_build_stemmed_operand" operand without change if no langage is defined.
And uses current langage in pages "acqui/neworderbiblio.pl" and "cataloguing/addbooks.pl" so all catalog search uses stemming.

Test plan :
1) Enable system preferences QueryStemming and QueryWeightFields
2) Disable system preferences QueryAutoTruncate, QueryFuzzy and UseQueryParser
3) Go to intranet main page and click on "Search the catalog" tab
4) Perform a search (without index) that uses the stemming, for example searching for "years" will also match "year"
5) Note how many results you get, for example "year" gets 24 results and "years" gets 24 results
6) Go to "Cataloging" module
7) Perform a search on same word in "Cataloging search" tab
8) Note how many results you get
9) Without patch you get fewer results than first search (step 5) because stemming is not applied, for example "year" gets 11 results and "years" gets 15 results
10) With patch you get the same results as first search (step 5) because stemming is applied, for example "year" and "years" gets 24 results
11) Same tests in aquisition module
12) On a basket, click "Add to basket" and perform a search in "From an existing record"

Signed-off-by: David Nind <david@davidnind.com>
---
 C4/Search.pm            | 3 +++
 acqui/neworderbiblio.pl | 5 ++++-
 cataloguing/addbooks.pl | 5 ++++-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/C4/Search.pm b/C4/Search.pm
index 06e837de03..46fafcda9d 100644
--- a/C4/Search.pm
+++ b/C4/Search.pm
@@ -968,6 +968,9 @@ sub _build_stemmed_operand {
     require Lingua::Stem::Snowball ;
     my $stemmed_operand=q{};
 
+    # Stemmer needs language
+    return $operand unless $lang;
+
     # If operand contains a digit, it is almost certainly an identifier, and should
     # not be stemmed.  This is particularly relevant for ISBNs and ISSNs, which
     # can contain the letter "X" - for example, _build_stemmend_operand would reduce
diff --git a/acqui/neworderbiblio.pl b/acqui/neworderbiblio.pl
index f083398e4f..b48737d79f 100755
--- a/acqui/neworderbiblio.pl
+++ b/acqui/neworderbiblio.pl
@@ -64,6 +64,7 @@ use C4::Auth;
 use C4::Output;
 use C4::Koha;
 use C4::Budgets qw/ GetBudgetHierarchy /;
+use C4::Languages qw(getlanguage);
 
 use Koha::Acquisition::Booksellers;
 use Koha::SearchEngine;
@@ -83,6 +84,7 @@ my $booksellerid     = $params->{'booksellerid'};
 my $basketno         = $params->{'basketno'};
 my $sub              = $params->{'sub'};
 my $bookseller       = Koha::Acquisition::Booksellers->find( $booksellerid );
+my $lang             = C4::Languages::getlanguage($input);
 
 # getting the template
 my ( $template, $loggedinuser, $cookie ) = get_template_and_user(
@@ -106,7 +108,8 @@ my $searcher = Koha::SearchEngine::Search->new({index => $Koha::SearchEngine::BI
 if ($QParser) {
     $builtquery = $query;
 } else {
-    ( undef,$builtquery,undef,undef,undef,undef,undef,undef,undef,undef) = $builder->build_query_compat(undef,\@operands);
+        ( undef, $builtquery, undef, undef, undef, undef, undef, undef, undef, undef ) =
+          $builder->build_query_compat( undef, \@operands, undef, undef, undef, 0, $lang );
 }
 my ( $error, $marcresults, $total_hits ) = $searcher->simple_search_compat($builtquery, $results_per_page * ($page - 1), $results_per_page);
 
diff --git a/cataloguing/addbooks.pl b/cataloguing/addbooks.pl
index 253683db1d..e374cd33ac 100755
--- a/cataloguing/addbooks.pl
+++ b/cataloguing/addbooks.pl
@@ -32,6 +32,7 @@ use C4::Biblio;
 use C4::Breeding;
 use C4::Output;
 use C4::Koha;
+use C4::Languages qw(getlanguage);
 use C4::Search;
 
 use Koha::BiblioFrameworks;
@@ -46,6 +47,7 @@ my $query   = $input->param('q');
 my @value   = $input->multi_param('value');
 my $page    = $input->param('page') || 1;
 my $results_per_page = 20;
+my $lang = C4::Languages::getlanguage($input);
 
 
 my ( $template, $loggedinuser, $cookie ) = get_template_and_user(
@@ -75,7 +77,8 @@ if ($query) {
     if ($QParser) {
         $builtquery = $query;
     } else {
-        ( undef,$builtquery,undef,undef,undef,undef,undef,undef,undef,undef) = $builder->build_query_compat(undef,\@operands);
+        ( undef, $builtquery, undef, undef, undef, undef, undef, undef, undef, undef ) =
+          $builder->build_query_compat( undef, \@operands, undef, undef, undef, 0, $lang );
     }
     # find results
     my ( $error, $marcresults, $total_hits ) = $searcher->simple_search_compat($builtquery, $results_per_page * ($page - 1), $results_per_page);
-- 
2.11.0