From aa725c0ccef96e6e71ca73088b76e7823af26f60 Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Mon, 22 Apr 2019 11:04:05 +0200
Subject: [PATCH 01/17] use nullable for datetime fields

---
 installation/sql/mysql/joomla.sql | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/installation/sql/mysql/joomla.sql b/installation/sql/mysql/joomla.sql
index 65230edbe122e..6b1e4914a2462 100644
--- a/installation/sql/mysql/joomla.sql
+++ b/installation/sql/mysql/joomla.sql
@@ -283,7 +283,7 @@ CREATE TABLE IF NOT EXISTS `#__contact_details` (
   `default_con` tinyint(1) unsigned NOT NULL DEFAULT 0,
   `published` tinyint(1) NOT NULL DEFAULT 0,
   `checked_out` int(10) unsigned NOT NULL DEFAULT 0,
-  `checked_out_time` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
+  `checked_out_time` datetime,
   `ordering` int(11) NOT NULL DEFAULT 0,
   `params` text NOT NULL,
   `user_id` int(11) NOT NULL DEFAULT 0,
@@ -298,15 +298,15 @@ CREATE TABLE IF NOT EXISTS `#__contact_details` (
   `created` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
   `created_by` int(10) unsigned NOT NULL DEFAULT 0,
   `created_by_alias` varchar(255) NOT NULL DEFAULT '',
-  `modified` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
+  `modified` datetime,
   `modified_by` int(10) unsigned NOT NULL DEFAULT 0,
   `metakey` text NOT NULL,
   `metadesc` text NOT NULL,
   `metadata` text NOT NULL,
   `featured` tinyint(3) unsigned NOT NULL DEFAULT 0 COMMENT 'Set if contact is featured.',
   `xreference` varchar(50) NOT NULL DEFAULT '' COMMENT 'A reference to enable linkages to external data sets.',
-  `publish_up` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
-  `publish_down` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
+  `publish_up` datetime,
+  `publish_down` datetime,
   `version` int(10) unsigned NOT NULL DEFAULT 1,
   `hits` int(10) unsigned NOT NULL DEFAULT 0,
   PRIMARY KEY (`id`),

From 84976de403c6ba69a7026d5b9ee440f27ba54d20 Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Mon, 22 Apr 2019 11:07:21 +0200
Subject: [PATCH 02/17] use nullable for timestamp fields

---
 installation/sql/postgresql/joomla.sql | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/installation/sql/postgresql/joomla.sql b/installation/sql/postgresql/joomla.sql
index 5c681314516f5..bfc956106ead8 100644
--- a/installation/sql/postgresql/joomla.sql
+++ b/installation/sql/postgresql/joomla.sql
@@ -288,7 +288,7 @@ CREATE TABLE IF NOT EXISTS "#__contact_details" (
   "default_con" smallint NOT NULL DEFAULT 0,
   "published" smallint NOT NULL DEFAULT 0,
   "checked_out" bigint NOT NULL DEFAULT 0,
-  "checked_out_time" timestamp without time zone NOT NULL DEFAULT '1970-01-01 00:00:00',
+  "checked_out_time" timestamp without time zone,
   "ordering" bigint NOT NULL DEFAULT 0,
   "params" text NOT NULL,
   "user_id" bigint NOT NULL DEFAULT 0,
@@ -303,15 +303,15 @@ CREATE TABLE IF NOT EXISTS "#__contact_details" (
   "created" timestamp without time zone NOT NULL DEFAULT '1970-01-01 00:00:00',
   "created_by" integer NOT NULL DEFAULT 0,
   "created_by_alias" varchar(255) NOT NULL DEFAULT '',
-  "modified" timestamp without time zone NOT NULL DEFAULT '1970-01-01 00:00:00',
+  "modified" timestamp without time zone,
   "modified_by" integer NOT NULL DEFAULT 0,
   "metakey" text NOT NULL,
   "metadesc" text NOT NULL,
   "metadata" text NOT NULL,
   "featured" smallint NOT NULL DEFAULT 0,
   "xreference" varchar(50) NOT NULL DEFAULT '',
-  "publish_up" timestamp without time zone NOT NULL DEFAULT '1970-01-01 00:00:00',
-  "publish_down" timestamp without time zone NOT NULL DEFAULT '1970-01-01 00:00:00',
+  "publish_up" timestamp without time zone,
+  "publish_down" timestamp without time zone,
   "version" bigint NOT NULL DEFAULT 1,
   "hits" bigint NOT NULL DEFAULT 0,
   PRIMARY KEY ("id")

From 29973538dc0fe119aa90bbd24291c988e86fcb70 Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Mon, 22 Apr 2019 11:10:03 +0200
Subject: [PATCH 03/17] nullable fields

---
 .../com_contact/Table/ContactTable.php        | 38 +++++++++++--------
 1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/administrator/components/com_contact/Table/ContactTable.php b/administrator/components/com_contact/Table/ContactTable.php
index 64d7dee246efa..ed2cbf6a8cf4e 100644
--- a/administrator/components/com_contact/Table/ContactTable.php
+++ b/administrator/components/com_contact/Table/ContactTable.php
@@ -27,6 +27,15 @@
  */
 class ContactTable extends Table
 {
+
+	/**
+	 * Indicates that columns fully support the NULL value in the database
+	 *
+	 * @var    boolean
+	 * @since  __DEPLOY_VERSION__
+	 */
+	protected $_supportNullValue = true;
+
 	/**
 	 * Ensure the params and metadata in json encoded in the bind method
 	 *
@@ -58,7 +67,7 @@ public function __construct(DatabaseDriver $db)
 	 *
 	 * @since   1.6
 	 */
-	public function store($updateNulls = false)
+	public function store($updateNulls = true)
 	{
 		// Transform the params field
 		if (is_array($this->params))
@@ -91,18 +100,6 @@ public function store($updateNulls = false)
 			}
 		}
 
-		// Set publish_up to null date if not set
-		if (!$this->publish_up)
-		{
-			$this->publish_up = $this->_db->getNullDate();
-		}
-
-		// Set publish_down to null date if not set
-		if (!$this->publish_down)
-		{
-			$this->publish_down = $this->_db->getNullDate();
-		}
-
 		// Set xreference to empty string if not set
 		if (!$this->xreference)
 		{
@@ -253,9 +250,20 @@ public function check()
 			$this->metadata = '{}';
 		}
 
-		if (empty($this->modified))
+		// Set publish_up, publish_down, modified to null if not set
+		if (!$this->publish_up)
+		{
+			$this->publish_up = null;
+		}
+
+		if (!$this->publish_down)
+		{
+			$this->publish_down = null;
+		}
+
+		if (!$this->modified)
 		{
-			$this->modified = $this->getDbo()->getNullDate();
+			$this->modified = null;
 		}
 
 		return true;

From 686f52be9a30b336a3905b72500362e846aa8a94 Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Mon, 22 Apr 2019 11:13:23 +0200
Subject: [PATCH 04/17] nullable fields

---
 components/com_contact/Model/ContactModel.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/components/com_contact/Model/ContactModel.php b/components/com_contact/Model/ContactModel.php
index 01b459ead0a3b..5dd24f4ecbc47 100644
--- a/components/com_contact/Model/ContactModel.php
+++ b/components/com_contact/Model/ContactModel.php
@@ -215,8 +215,8 @@ public function getItem($pk = null)
 				if (is_numeric($published))
 				{
 					$query->where('(a.published = ' . (int) $published . ' OR a.published =' . (int) $archived . ')')
-						->where('(a.publish_up = ' . $nullDate . ' OR a.publish_up <= ' . $nowDate . ')')
-						->where('(a.publish_down = ' . $nullDate . ' OR a.publish_down >= ' . $nowDate . ')');
+						->where('(' . $query->isNullDatetime('a.publish_up') . ' OR a.publish_up <= ' . $db->quote($nowDate) . ')')
+						->where('(' . $query->isNullDatetime('a.publish_down') . ' OR a.publish_down >= ' . $db->quote($nowDate) . ')');
 				}
 
 				$db->setQuery($query);

From abe4fa891a7da0348b03132bbf5ea19d9f891b70 Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Mon, 22 Apr 2019 11:15:24 +0200
Subject: [PATCH 05/17] nullable fields

---
 components/com_contact/Model/CategoryModel.php | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/components/com_contact/Model/CategoryModel.php b/components/com_contact/Model/CategoryModel.php
index bbfb193c941bd..83978df802513 100644
--- a/components/com_contact/Model/CategoryModel.php
+++ b/components/com_contact/Model/CategoryModel.php
@@ -179,9 +179,9 @@ protected function getListQuery()
 		$nowDate = $db->quote(Factory::getDate()->toSql());
 
 		if ($this->getState('filter.publish_date'))
-		{
-			$query->where('(a.publish_up = ' . $nullDate . ' OR a.publish_up <= ' . $nowDate . ')')
-				->where('(a.publish_down = ' . $nullDate . ' OR a.publish_down >= ' . $nowDate . ')');
+		{			
+			$query->where('(' . $query->isNullDatetime('a.publish_up') . ' OR a.publish_up <= ' . $db->quote($nowDate) . ')')
+				->where('(' . $query->isNullDatetime('a.publish_down') . ' OR a.publish_down >= ' . $db->quote($nowDate) . ')');
 		}
 
 		// Filter by search in title

From ef9742f5146ad3c65f794f85068ed0188add2ce0 Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Mon, 22 Apr 2019 11:28:22 +0200
Subject: [PATCH 06/17] blank line

---
 administrator/components/com_contact/Table/ContactTable.php | 1 -
 1 file changed, 1 deletion(-)

diff --git a/administrator/components/com_contact/Table/ContactTable.php b/administrator/components/com_contact/Table/ContactTable.php
index ed2cbf6a8cf4e..453adb02cdc18 100644
--- a/administrator/components/com_contact/Table/ContactTable.php
+++ b/administrator/components/com_contact/Table/ContactTable.php
@@ -27,7 +27,6 @@
  */
 class ContactTable extends Table
 {
-
 	/**
 	 * Indicates that columns fully support the NULL value in the database
 	 *

From 61d847d64d841a998cb3e4b44faa19edb40db844 Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Mon, 22 Apr 2019 11:29:33 +0200
Subject: [PATCH 07/17] spaces removed

---
 components/com_contact/Model/CategoryModel.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/components/com_contact/Model/CategoryModel.php b/components/com_contact/Model/CategoryModel.php
index 83978df802513..02e32764fdb83 100644
--- a/components/com_contact/Model/CategoryModel.php
+++ b/components/com_contact/Model/CategoryModel.php
@@ -179,7 +179,7 @@ protected function getListQuery()
 		$nowDate = $db->quote(Factory::getDate()->toSql());
 
 		if ($this->getState('filter.publish_date'))
-		{			
+		{
 			$query->where('(' . $query->isNullDatetime('a.publish_up') . ' OR a.publish_up <= ' . $db->quote($nowDate) . ')')
 				->where('(' . $query->isNullDatetime('a.publish_down') . ' OR a.publish_down >= ' . $db->quote($nowDate) . ')');
 		}

From a80f575569e7eea90e9c948e5d431e32483f8cb5 Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Mon, 22 Apr 2019 11:36:22 +0200
Subject: [PATCH 08/17] sql update

---
 .../com_admin/sql/updates/mysql/4.0.0-2019-04-22.sql  | 11 +++++++++++
 1 file changed, 11 insertions(+)
 create mode 100644 administrator/components/com_admin/sql/updates/mysql/4.0.0-2019-04-22.sql

diff --git a/administrator/components/com_admin/sql/updates/mysql/4.0.0-2019-04-22.sql b/administrator/components/com_admin/sql/updates/mysql/4.0.0-2019-04-22.sql
new file mode 100644
index 0000000000000..fc1306b2df455
--- /dev/null
+++ b/administrator/components/com_admin/sql/updates/mysql/4.0.0-2019-04-22.sql
@@ -0,0 +1,11 @@
+ALTER TABLE `#__contact_details` MODIFY `publish_up` datetime NULL DEFAULT NULL;
+ALTER TABLE `#__contact_details` MODIFY `publish_down` datetime NULL DEFAULT NULL;
+ALTER TABLE `#__contact_details` MODIFY `checked_out_time` datetime NULL DEFAULT NULL;
+ALTER TABLE `#__contact_details` MODIFY `modified` datetime NULL DEFAULT NULL;
+
+
+UPDATE `#__contact_details` SET
+	`publish_up` = CASE WHEN `publish_up` IN ('0000-00-00 00:00:00', '1000-01-01 00:00:00') THEN NULL ELSE `publish_up` END,
+	`publish_down` = CASE WHEN `publish_down` IN ('0000-00-00 00:00:00', '1000-01-01 00:00:00') THEN NULL ELSE `publish_down` END,
+	`checked_out_time` = CASE WHEN `checked_out_time` IN ('0000-00-00 00:00:00', '1000-01-01 00:00:00') THEN NULL ELSE `checked_out_time` END,
+	`modified` = CASE WHEN `modified` IN ('0000-00-00 00:00:00', '1000-01-01 00:00:00') THEN NULL ELSE `modified` END;

From 404733d4aef0f70dd6917807a4598be4c8d05ce5 Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Mon, 22 Apr 2019 11:42:24 +0200
Subject: [PATCH 09/17] sql updates

---
 .../sql/updates/postgresql/4.0.0-2019-04-22.sql | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 administrator/components/com_admin/sql/updates/postgresql/4.0.0-2019-04-22.sql

diff --git a/administrator/components/com_admin/sql/updates/postgresql/4.0.0-2019-04-22.sql b/administrator/components/com_admin/sql/updates/postgresql/4.0.0-2019-04-22.sql
new file mode 100644
index 0000000000000..70c959029ea35
--- /dev/null
+++ b/administrator/components/com_admin/sql/updates/postgresql/4.0.0-2019-04-22.sql
@@ -0,0 +1,17 @@
+ALTER TABLE "#__contact_details" ALTER COLUMN "publish_up" DROP NOT NULL;
+ALTER TABLE "#__contact_details" ALTER COLUMN "publish_up" DROP DEFAULT;
+
+ALTER TABLE "#__contact_details" ALTER COLUMN "publish_down" DROP NOT NULL;
+ALTER TABLE "#__contact_details" ALTER COLUMN "publish_down" DROP DEFAULT;
+
+ALTER TABLE "#__contact_details" ALTER COLUMN "checked_out_time" DROP NOT NULL;
+ALTER TABLE "#__contact_details" ALTER COLUMN "checked_out_time" DROP DEFAULT;
+
+ALTER TABLE "#__contact_details" ALTER COLUMN "modified" DROP NOT NULL;
+ALTER TABLE "#__contact_details" ALTER COLUMN "modified" DROP DEFAULT;
+
+UPDATE "#__contact_details" SET
+	"publish_up" = CASE WHEN "publish_up" = '1970-01-01 00:00:00' THEN NULL ELSE "publish_up" END,
+	"publish_down" = CASE WHEN "publish_down" = '1970-01-01 00:00:00' THEN NULL ELSE "publish_down" END,
+	"checked_out_time" = CASE WHEN "checked_out_time" = '1970-01-01 00:00:00' THEN NULL ELSE "checked_out_time" END,
+	"modified" = CASE WHEN "modified" = '1970-01-01 00:00:00' THEN NULL ELSE "modified" END;

From e42342e1eac32360a37597cfb4dc3846f3b69eb4 Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Mon, 22 Apr 2019 11:57:53 +0200
Subject: [PATCH 10/17] featured

---
 components/com_contact/Model/FeaturedModel.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/components/com_contact/Model/FeaturedModel.php b/components/com_contact/Model/FeaturedModel.php
index 1a2148f228edb..1368557428f4e 100644
--- a/components/com_contact/Model/FeaturedModel.php
+++ b/components/com_contact/Model/FeaturedModel.php
@@ -118,8 +118,8 @@ protected function getListQuery()
 			$date = Factory::getDate();
 			$nowDate = $db->quote($date->toSql());
 
-			$query->where('(a.publish_up = ' . $nullDate . ' OR a.publish_up <= ' . $nowDate . ')')
-				->where('(a.publish_down = ' . $nullDate . ' OR a.publish_down >= ' . $nowDate . ')');
+			$query->where('(' . $query->isNullDatetime('a.publish_up') . ' OR a.publish_up <= ' . $db->quote($nowDate) . ')')
+				->where('(' . $query->isNullDatetime('a.publish_down') . ' OR a.publish_down >= ' . $db->quote($nowDate). ')');
 		}
 
 		// Filter by language

From 44b90c5a7778dba24f249b8dba0d4f4ac6db08d7 Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Mon, 22 Apr 2019 12:35:58 +0200
Subject: [PATCH 11/17] cs

---
 components/com_contact/Model/FeaturedModel.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/components/com_contact/Model/FeaturedModel.php b/components/com_contact/Model/FeaturedModel.php
index 1368557428f4e..96c4129265070 100644
--- a/components/com_contact/Model/FeaturedModel.php
+++ b/components/com_contact/Model/FeaturedModel.php
@@ -119,7 +119,7 @@ protected function getListQuery()
 			$nowDate = $db->quote($date->toSql());
 
 			$query->where('(' . $query->isNullDatetime('a.publish_up') . ' OR a.publish_up <= ' . $db->quote($nowDate) . ')')
-				->where('(' . $query->isNullDatetime('a.publish_down') . ' OR a.publish_down >= ' . $db->quote($nowDate). ')');
+				->where('(' . $query->isNullDatetime('a.publish_down') . ' OR a.publish_down >= ' . $db->quote($nowDate) . ')');
 		}
 
 		// Filter by language

From 05d069609ce2dd1ad75798fce88e9fe24817ef02 Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Tue, 7 May 2019 20:44:20 +0200
Subject: [PATCH 12/17] modified is not nullable

---
 .../com_admin/sql/updates/mysql/4.0.0-2019-04-22.sql         | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/administrator/components/com_admin/sql/updates/mysql/4.0.0-2019-04-22.sql b/administrator/components/com_admin/sql/updates/mysql/4.0.0-2019-04-22.sql
index fc1306b2df455..9459c3d8abaaa 100644
--- a/administrator/components/com_admin/sql/updates/mysql/4.0.0-2019-04-22.sql
+++ b/administrator/components/com_admin/sql/updates/mysql/4.0.0-2019-04-22.sql
@@ -1,11 +1,8 @@
 ALTER TABLE `#__contact_details` MODIFY `publish_up` datetime NULL DEFAULT NULL;
 ALTER TABLE `#__contact_details` MODIFY `publish_down` datetime NULL DEFAULT NULL;
 ALTER TABLE `#__contact_details` MODIFY `checked_out_time` datetime NULL DEFAULT NULL;
-ALTER TABLE `#__contact_details` MODIFY `modified` datetime NULL DEFAULT NULL;
-
 
 UPDATE `#__contact_details` SET
 	`publish_up` = CASE WHEN `publish_up` IN ('0000-00-00 00:00:00', '1000-01-01 00:00:00') THEN NULL ELSE `publish_up` END,
 	`publish_down` = CASE WHEN `publish_down` IN ('0000-00-00 00:00:00', '1000-01-01 00:00:00') THEN NULL ELSE `publish_down` END,
-	`checked_out_time` = CASE WHEN `checked_out_time` IN ('0000-00-00 00:00:00', '1000-01-01 00:00:00') THEN NULL ELSE `checked_out_time` END,
-	`modified` = CASE WHEN `modified` IN ('0000-00-00 00:00:00', '1000-01-01 00:00:00') THEN NULL ELSE `modified` END;
+	`checked_out_time` = CASE WHEN `checked_out_time` IN ('0000-00-00 00:00:00', '1000-01-01 00:00:00') THEN NULL ELSE `checked_out_time` END;

From fb77ab387f0aa707b874a691a03031116ed2dd4f Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Tue, 7 May 2019 20:45:17 +0200
Subject: [PATCH 13/17] modifyed is not nullable

---
 .../com_admin/sql/updates/postgresql/4.0.0-2019-04-22.sql   | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/administrator/components/com_admin/sql/updates/postgresql/4.0.0-2019-04-22.sql b/administrator/components/com_admin/sql/updates/postgresql/4.0.0-2019-04-22.sql
index 70c959029ea35..32d91acc14636 100644
--- a/administrator/components/com_admin/sql/updates/postgresql/4.0.0-2019-04-22.sql
+++ b/administrator/components/com_admin/sql/updates/postgresql/4.0.0-2019-04-22.sql
@@ -7,11 +7,7 @@ ALTER TABLE "#__contact_details" ALTER COLUMN "publish_down" DROP DEFAULT;
 ALTER TABLE "#__contact_details" ALTER COLUMN "checked_out_time" DROP NOT NULL;
 ALTER TABLE "#__contact_details" ALTER COLUMN "checked_out_time" DROP DEFAULT;
 
-ALTER TABLE "#__contact_details" ALTER COLUMN "modified" DROP NOT NULL;
-ALTER TABLE "#__contact_details" ALTER COLUMN "modified" DROP DEFAULT;
-
 UPDATE "#__contact_details" SET
 	"publish_up" = CASE WHEN "publish_up" = '1970-01-01 00:00:00' THEN NULL ELSE "publish_up" END,
 	"publish_down" = CASE WHEN "publish_down" = '1970-01-01 00:00:00' THEN NULL ELSE "publish_down" END,
-	"checked_out_time" = CASE WHEN "checked_out_time" = '1970-01-01 00:00:00' THEN NULL ELSE "checked_out_time" END,
-	"modified" = CASE WHEN "modified" = '1970-01-01 00:00:00' THEN NULL ELSE "modified" END;
+	"checked_out_time" = CASE WHEN "checked_out_time" = '1970-01-01 00:00:00' THEN NULL ELSE "checked_out_time" END;

From 0c173d9b3749bf043cc35c34cd694cb8cfca03f9 Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Tue, 7 May 2019 20:46:47 +0200
Subject: [PATCH 14/17] modified is not nullable

---
 administrator/components/com_contact/Table/ContactTable.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/administrator/components/com_contact/Table/ContactTable.php b/administrator/components/com_contact/Table/ContactTable.php
index 453adb02cdc18..d6d60a300c071 100644
--- a/administrator/components/com_contact/Table/ContactTable.php
+++ b/administrator/components/com_contact/Table/ContactTable.php
@@ -262,7 +262,7 @@ public function check()
 
 		if (!$this->modified)
 		{
-			$this->modified = null;
+			$this->modified = $this->created;
 		}
 
 		return true;

From a39380f5fc88860830d287b2ee72cd0ad016303e Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Tue, 7 May 2019 20:48:26 +0200
Subject: [PATCH 15/17] modified is not nullable

---
 installation/sql/mysql/joomla.sql | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/installation/sql/mysql/joomla.sql b/installation/sql/mysql/joomla.sql
index 6b1e4914a2462..5f1754382ec53 100644
--- a/installation/sql/mysql/joomla.sql
+++ b/installation/sql/mysql/joomla.sql
@@ -298,7 +298,7 @@ CREATE TABLE IF NOT EXISTS `#__contact_details` (
   `created` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
   `created_by` int(10) unsigned NOT NULL DEFAULT 0,
   `created_by_alias` varchar(255) NOT NULL DEFAULT '',
-  `modified` datetime,
+  `modified` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
   `modified_by` int(10) unsigned NOT NULL DEFAULT 0,
   `metakey` text NOT NULL,
   `metadesc` text NOT NULL,

From b8b49a1f07dd316caba13dc418d93c787cb7b560 Mon Sep 17 00:00:00 2001
From: Nicola Galgano <optimus4joomla@gmail.com>
Date: Tue, 7 May 2019 20:50:26 +0200
Subject: [PATCH 16/17] modified is not nullable

---
 installation/sql/postgresql/joomla.sql | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/installation/sql/postgresql/joomla.sql b/installation/sql/postgresql/joomla.sql
index bfc956106ead8..3ce2e8d3802ef 100644
--- a/installation/sql/postgresql/joomla.sql
+++ b/installation/sql/postgresql/joomla.sql
@@ -303,7 +303,7 @@ CREATE TABLE IF NOT EXISTS "#__contact_details" (
   "created" timestamp without time zone NOT NULL DEFAULT '1970-01-01 00:00:00',
   "created_by" integer NOT NULL DEFAULT 0,
   "created_by_alias" varchar(255) NOT NULL DEFAULT '',
-  "modified" timestamp without time zone,
+  "modified" timestamp without time zone NOT NULL DEFAULT '1970-01-01 00:00:00',
   "modified_by" integer NOT NULL DEFAULT 0,
   "metakey" text NOT NULL,
   "metadesc" text NOT NULL,

From c5ae1414988e75d38a55493ed595e272d17a0317 Mon Sep 17 00:00:00 2001
From: Quy <quy@fluxbb.org>
Date: Tue, 7 May 2019 21:29:41 +0200
Subject: [PATCH 17/17] Update
 administrator/components/com_contact/Table/ContactTable.php

Co-Authored-By: alikon <optimus4joomla@gmail.com>
---
 administrator/components/com_contact/Table/ContactTable.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/administrator/components/com_contact/Table/ContactTable.php b/administrator/components/com_contact/Table/ContactTable.php
index d6d60a300c071..04f53ce83dc45 100644
--- a/administrator/components/com_contact/Table/ContactTable.php
+++ b/administrator/components/com_contact/Table/ContactTable.php
@@ -249,7 +249,7 @@ public function check()
 			$this->metadata = '{}';
 		}
 
-		// Set publish_up, publish_down, modified to null if not set
+		// Set publish_up, publish_down to null if not set
 		if (!$this->publish_up)
 		{
 			$this->publish_up = null;