From 55ef9f0564c4a6794dd6ce4794e3776ea11fc12d Mon Sep 17 00:00:00 2001
From: michalsn <michal@sniatala.pl>
Date: Tue, 12 Aug 2025 21:05:51 +0200
Subject: [PATCH 1/2] fix: prevent non-shared DB instances from polluting
 shared cache

---
 system/Database/Config.php                  |  4 +++-
 tests/system/Database/Live/ConnectTest.php  | 18 ++++++++++++++++++
 user_guide_src/source/changelogs/v4.6.4.rst |  2 ++
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/system/Database/Config.php b/system/Database/Config.php
index 6f25ad3c0059..fcf700ee3bcb 100644
--- a/system/Database/Config.php
+++ b/system/Database/Config.php
@@ -81,7 +81,9 @@ public static function connect($group = null, bool $getShared = true)
 
         $connection = static::$factory->load($config, $group);
 
-        static::$instances[$group] = $connection;
+        if ($getShared) {
+            static::$instances[$group] = $connection;
+        }
 
         return $connection;
     }
diff --git a/tests/system/Database/Live/ConnectTest.php b/tests/system/Database/Live/ConnectTest.php
index 3f7941a201ec..e41fdbdfc114 100644
--- a/tests/system/Database/Live/ConnectTest.php
+++ b/tests/system/Database/Live/ConnectTest.php
@@ -115,4 +115,22 @@ public function testConnectWithFailover(): void
 
         $this->assertGreaterThanOrEqual(0, count($db1->listTables()));
     }
+
+    public function testNonSharedInstanceDoesNotAffectSharedInstances(): void
+    {
+        $firstSharedDb      = Database::connect('tests');
+        $originalDebugValue = (bool) self::getPrivateProperty($firstSharedDb, 'DBDebug');
+
+        $nonSharedDb = Database::connect('tests', false);
+        self::setPrivateProperty($nonSharedDb, 'DBDebug', ! $originalDebugValue);
+
+        $secondSharedDb = Database::connect('tests');
+
+        $this->assertSame($firstSharedDb, $secondSharedDb);
+        $this->assertNotSame($firstSharedDb, $nonSharedDb);
+
+        $this->assertSame($originalDebugValue, self::getPrivateProperty($firstSharedDb, 'DBDebug'));
+        $this->assertSame($originalDebugValue, self::getPrivateProperty($secondSharedDb, 'DBDebug'));
+        $this->assertSame(! $originalDebugValue, self::getPrivateProperty($nonSharedDb, 'DBDebug'));
+    }
 }
diff --git a/user_guide_src/source/changelogs/v4.6.4.rst b/user_guide_src/source/changelogs/v4.6.4.rst
index 7cae67431354..dfe8bd86dd29 100644
--- a/user_guide_src/source/changelogs/v4.6.4.rst
+++ b/user_guide_src/source/changelogs/v4.6.4.rst
@@ -30,6 +30,8 @@ Deprecations
 Bugs Fixed
 **********
 
+- **Database:** Fixed a bug in ``Database::connect()`` which was causing storing non-shared connection instances in shared cache.
+
 See the repo's
 `CHANGELOG.md <https://github.com/codeigniter4/CodeIgniter4/blob/develop/CHANGELOG.md>`_
 for a complete list of bugs fixed.

From bca4d82d58b616a79f06dd28427d6df1c6380613 Mon Sep 17 00:00:00 2001
From: Michal Sniatala <michal@sniatala.pl>
Date: Wed, 13 Aug 2025 06:52:39 +0200
Subject: [PATCH 2/2] Update user_guide_src/source/changelogs/v4.6.4.rst

Co-authored-by: John Paul E. Balandan, CPA <paulbalandan@gmail.com>
---
 user_guide_src/source/changelogs/v4.6.4.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/user_guide_src/source/changelogs/v4.6.4.rst b/user_guide_src/source/changelogs/v4.6.4.rst
index dfe8bd86dd29..8ef80eabbfcf 100644
--- a/user_guide_src/source/changelogs/v4.6.4.rst
+++ b/user_guide_src/source/changelogs/v4.6.4.rst
@@ -30,7 +30,7 @@ Deprecations
 Bugs Fixed
 **********
 
-- **Database:** Fixed a bug in ``Database::connect()`` which was causing storing non-shared connection instances in shared cache.
+- **Database:** Fixed a bug in ``Database::connect()`` which was causing to store non-shared connection instances in shared cache.
 
 See the repo's
 `CHANGELOG.md <https://github.com/codeigniter4/CodeIgniter4/blob/develop/CHANGELOG.md>`_