From 8fae10a971e982771e59dc60811b7cc5add57d1e Mon Sep 17 00:00:00 2001
From: Graeme Tait <burriko@gmail.com>
Date: Mon, 21 Sep 2015 14:05:56 +0100
Subject: [PATCH 1/3] Set DboSource::$_connection to null on disconnect

---
 lib/Cake/Model/Datasource/DboSource.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/Cake/Model/Datasource/DboSource.php b/lib/Cake/Model/Datasource/DboSource.php
index a41e88cef..e66ff49c1 100644
--- a/lib/Cake/Model/Datasource/DboSource.php
+++ b/lib/Cake/Model/Datasource/DboSource.php
@@ -284,7 +284,7 @@ class DboSource extends DataSource {
 		if ($this->_result instanceof PDOStatement) {
 			$this->_result->closeCursor();
 		}
-		unset($this->_connection);
+		$this->_connection = null;
 		$this->connected = false;
 		return true;
 	}

From 1b33efaad3b3e9af87074552127839375d3cedee Mon Sep 17 00:00:00 2001
From: Graeme Tait <burriko@gmail.com>
Date: Mon, 21 Sep 2015 14:08:07 +0100
Subject: [PATCH 2/3] Check $_connection is not null before trying to use it

Stops a fatal error if calling isConnected() after disconnect().
---
 lib/Cake/Model/Datasource/DboSource.php | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/lib/Cake/Model/Datasource/DboSource.php b/lib/Cake/Model/Datasource/DboSource.php
index e66ff49c1..135dfe055 100644
--- a/lib/Cake/Model/Datasource/DboSource.php
+++ b/lib/Cake/Model/Datasource/DboSource.php
@@ -857,10 +857,14 @@ class DboSource extends DataSource {
  * @return bool True if the database is connected, else false
  */
 	public function isConnected() {
-		try {
-			$connected = $this->_connection->query('SELECT 1');
-		} catch (Exception $e) {
+		if (is_null($this->_connection)) {
 			$connected = false;
+		} else {
+			try {
+				$connected = $this->_connection->query('SELECT 1');
+			} catch (Exception $e) {
+				$connected = false;
+			}
 		}
 		$this->connected = ! empty($connected);
 		return $this->connected;

From dc856b850865589f9810cf93bc12187902174bc9 Mon Sep 17 00:00:00 2001
From: Graeme Tait <burriko@gmail.com>
Date: Mon, 21 Sep 2015 17:00:20 +0100
Subject: [PATCH 3/3] Switch out is_null()

---
 lib/Cake/Model/Datasource/DboSource.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/Cake/Model/Datasource/DboSource.php b/lib/Cake/Model/Datasource/DboSource.php
index 135dfe055..b3ae8d814 100644
--- a/lib/Cake/Model/Datasource/DboSource.php
+++ b/lib/Cake/Model/Datasource/DboSource.php
@@ -857,7 +857,7 @@ class DboSource extends DataSource {
  * @return bool True if the database is connected, else false
  */
 	public function isConnected() {
-		if (is_null($this->_connection)) {
+		if ($this->_connection === null) {
 			$connected = false;
 		} else {
 			try {