From 849d2ac9ad9a97d4fcc0a6594d503615fa5ce37b Mon Sep 17 00:00:00 2001
From: Kenichi Ishigaki <ishigaki@cpan.org>
Date: Sat, 27 Jan 2018 12:34:47 +0900
Subject: [PATCH] Add a regression test for RT-124227

---
 MANIFEST                       |  1 +
 t/rt_124227_index_regression.t | 74 ++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+)
 create mode 100644 t/rt_124227_index_regression.t

diff --git a/MANIFEST b/MANIFEST
index fee016a..4dfc3c8 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -92,6 +92,7 @@ t/lib/SQLiteTest.pm
 t/rt_106151_outermost_savepoint.t
 t/rt_106950_extra_warnings_with_savepoints.t
 t/rt_115465_column_info_with_spaces.t
+t/rt_124227_index_regression.t
 t/rt_15186_prepcached.t
 t/rt_21406_auto_finish.t
 t/rt_25371_asymmetric_unicode.t
diff --git a/t/rt_124227_index_regression.t b/t/rt_124227_index_regression.t
new file mode 100644
index 0000000..cb55710
--- /dev/null
+++ b/t/rt_124227_index_regression.t
@@ -0,0 +1,74 @@
+use strict;
+use warnings;
+use lib "t/lib";
+use SQLiteTest;
+use Test::More;
+use Test::NoWarnings;
+
+plan tests => 5;
+
+my $sql_in_question = <<'EOS';
+SELECT cdid
+  FROM cd me
+WHERE 2 > (
+  SELECT COUNT( * )
+    FROM cd rownum__emulation
+  WHERE
+    (
+      me.genreid IS NOT NULL
+        AND
+      rownum__emulation.genreid IS NULL
+    )
+      OR
+    (
+      me.genreid IS NOT NULL
+        AND
+      rownum__emulation.genreid IS NOT NULL
+        AND
+      rownum__emulation.genreid < me.genreid
+    )
+      OR
+    (
+      ( me.genreid = rownum__emulation.genreid OR ( me.genreid IS NULL AND rownum__emulation.genreid IS NULL ) )
+        AND
+      rownum__emulation.cdid > me.cdid
+    )
+)
+EOS
+
+{ # With an index
+  my $dbh = connect_ok();
+  $dbh->do($_) for (
+    'CREATE TABLE cd ( cdid INTEGER PRIMARY KEY NOT NULL, genreid integer )',
+    'CREATE INDEX cd_idx_genreid ON cd (genreid)',
+    'INSERT INTO cd  ( cdid, genreid ) VALUES
+                   ( 1,    1 ),
+                   ( 2, NULL ),
+                   ( 3, NULL ),
+                   ( 4, NULL ),
+                   ( 5, NULL )
+    ',
+  );
+
+  my $res = $dbh->selectall_arrayref($sql_in_question);
+
+  is_deeply $res => [[4], [5]], "got the expected result with the index" or note explain $res;
+}
+
+{ # Without the index
+  my $dbh = connect_ok();
+  $dbh->do($_) for (
+    'CREATE TABLE cd ( cdid INTEGER PRIMARY KEY NOT NULL, genreid integer )',
+    'INSERT INTO cd  ( cdid, genreid ) VALUES
+                   ( 1,    1 ),
+                   ( 2, NULL ),
+                   ( 3, NULL ),
+                   ( 4, NULL ),
+                   ( 5, NULL )
+    ',
+  );
+
+  my $res = $dbh->selectall_arrayref($sql_in_question);
+
+  is_deeply $res => [[4], [5]], "got the expected result without the index" or note explain $res;
+}