Merge pull request #9010 from kenjis/fix-qb-select-null-escape

fix: [QueryBuilder] `select()` does not escape after `NULL`

Author: kenjis

system/Database/BaseBuilder.php

@@ -430,8 +430,10 @@ 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) {
-                    $escape = false;
+                if (mb_stripos($val, 'NULL') === 0) {
+                    $this->QBNoEscape[] = false;
+
+                    continue;
                 }
 
                 $this->QBNoEscape[] = $escape;

tests/system/Database/Builder/SelectTest.php

@@ -160,6 +160,28 @@ 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
      */