From 6c81fa2879ae84abd342e6c7e688d2524e259244 Mon Sep 17 00:00:00 2001
From: William Desportes <williamdes@wdes.fr>
Date: Fri, 14 May 2021 14:21:47 +0200
Subject: [PATCH] Fix #16734 - SQL group by count results are not accurate

Signed-off-by: William Desportes <williamdes@wdes.fr>
---
 libraries/classes/Sql.php       |  9 ++-------
 test/classes/Stubs/DbiDummy.php | 10 ++++++----
 2 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/libraries/classes/Sql.php b/libraries/classes/Sql.php
index 8cde36c757..6fcaee9fc4 100644
--- a/libraries/classes/Sql.php
+++ b/libraries/classes/Sql.php
@@ -803,11 +803,6 @@ class Sql
                 $statement = $analyzed_sql_results['statement'];
                 $token_list = $analyzed_sql_results['parser']->list;
                 $replaces = [
-                    // Replace select by COUNT
-                    [
-                        'SELECT',
-                        'SELECT COUNT(*)',
-                    ],
                     // Remove ORDER BY to decrease unnecessary sorting time
                     [
                         'ORDER BY',
@@ -819,11 +814,11 @@ class Sql
                         '',
                     ],
                 ];
-                $count_query = Query::replaceClauses(
+                $count_query = 'SELECT COUNT(*) FROM (' . Query::replaceClauses(
                     $statement,
                     $token_list,
                     $replaces
-                );
+                ) . ') as cnt';
                 $unlim_num_rows = $this->dbi->fetchValue($count_query);
                 if ($unlim_num_rows === false) {
                     $unlim_num_rows = 0;
diff --git a/test/classes/Stubs/DbiDummy.php b/test/classes/Stubs/DbiDummy.php
index c27d2db387..d327b7209f 100644
--- a/test/classes/Stubs/DbiDummy.php
+++ b/test/classes/Stubs/DbiDummy.php
@@ -2405,17 +2405,17 @@ class DbiDummy implements DbiExtension
                 ],
             ],
             [
-                'query' => 'SELECT COUNT(*) FROM company_users WHERE not_working_count != 0',
+                'query' => 'SELECT COUNT(*) FROM (SELECT * FROM company_users WHERE not_working_count != 0 ) as cnt',
                 'result' => false,
             ],
             [
-                'query' => 'SELECT COUNT(*) FROM company_users',
+                'query' => 'SELECT COUNT(*) FROM (SELECT * FROM company_users ) as cnt',
                 'result' => [
                     [4],
                 ],
             ],
             [
-                'query' => 'SELECT COUNT(*) FROM company_users WHERE working_count = 0',
+                'query' => 'SELECT COUNT(*) FROM (SELECT * FROM company_users WHERE working_count = 0 ) as cnt',
                 'result' => [
                     [15],
                 ],
@@ -2427,7 +2427,9 @@ class DbiDummy implements DbiExtension
                 ],
             ],
             [
-                'query' => 'SELECT COUNT(*) FROM company_users WHERE subquery_case = 0',
+                'query' => 'SELECT COUNT(*) FROM ('
+                . 'SELECT *, 1, (SELECT COUNT(*) FROM tbl1) as c1, '
+                . '(SELECT 1 FROM tbl2) as c2 FROM company_users WHERE subquery_case = 0 ) as cnt',
                 'result' => [
                     [42],
                 ],