From 3f24caff8f0695c6a5ac185f046e67682d2648b1 Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 28 Jun 2024 09:33:32 +0900
Subject: [PATCH 1/3] test: add tests for `SELECT NULL as`

---
 tests/system/Database/Builder/SelectTest.php | 22 ++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/tests/system/Database/Builder/SelectTest.php b/tests/system/Database/Builder/SelectTest.php
index cd3f39029f6b..a761706dd3df 100644
--- a/tests/system/Database/Builder/SelectTest.php
+++ b/tests/system/Database/Builder/SelectTest.php
@@ -100,6 +100,28 @@ public function testSelectWorksWithComplexSelects(): void
         $this->assertSame($expected, str_replace("\n", ' ', $builder->getCompiledSelect()));
     }
 
+    public function testSelectNullAsInString(): void
+    {
+        $builder = new BaseBuilder('users', $this->db);
+
+        $builder->select('NULL as field_alias, name');
+
+        $expected = 'SELECT NULL as field_alias, "name" FROM "users"';
+
+        $this->assertSame($expected, str_replace("\n", ' ', $builder->getCompiledSelect()));
+    }
+
+    public function testSelectNullAsInArray(): void
+    {
+        $builder = new BaseBuilder('users', $this->db);
+
+        $builder->select(['NULL as field_alias', 'name']);
+
+        $expected = 'SELECT NULL as field_alias, "name" FROM "users"';
+
+        $this->assertSame($expected, str_replace("\n", ' ', $builder->getCompiledSelect()));
+    }
+
     /**
      * @see https://github.com/codeigniter4/CodeIgniter4/issues/4355
      */

From 6ba48cf061e28321986b0cc389e0bab41380082d Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 28 Jun 2024 09:34:14 +0900
Subject: [PATCH 2/3] fix: select() does not escape after `NULL as`

---
 system/Database/BaseBuilder.php | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/system/Database/BaseBuilder.php b/system/Database/BaseBuilder.php
index 4e6e422b2a6f..fab19b60dab8 100644
--- a/system/Database/BaseBuilder.php
+++ b/system/Database/BaseBuilder.php
@@ -425,7 +425,9 @@ public function select($select = '*', ?bool $escape = null)
                  * @see https://github.com/codeigniter4/CodeIgniter4/issues/1169
                  */
                 if (mb_stripos(trim($val), 'NULL') === 0) {
-                    $escape = false;
+                    $this->QBNoEscape[] = false;
+
+                    continue;
                 }
 
                 $this->QBNoEscape[] = $escape;

From 227f53a6cdaf1f1a7156c0e588e70625214ce920 Mon Sep 17 00:00:00 2001
From: kenjis <kenji.uui@gmail.com>
Date: Fri, 28 Jun 2024 09:39:06 +0900
Subject: [PATCH 3/3] refactor: remove duplicated `trim()`

It is already trimmed in Line 415.
---
 system/Database/BaseBuilder.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/system/Database/BaseBuilder.php b/system/Database/BaseBuilder.php
index fab19b60dab8..acfaa9e9183c 100644
--- a/system/Database/BaseBuilder.php
+++ b/system/Database/BaseBuilder.php
@@ -424,7 +424,7 @@ public function select($select = '*', ?bool $escape = null)
                  * This prevents NULL being escaped
                  * @see https://github.com/codeigniter4/CodeIgniter4/issues/1169
                  */
-                if (mb_stripos(trim($val), 'NULL') === 0) {
+                if (mb_stripos($val, 'NULL') === 0) {
                     $this->QBNoEscape[] = false;
 
                     continue;