Next item structure works (#5380)

* Use "LEFT JOIN" to always fetch the item. Needed for update routines. * New conversion routine that now covers every item * Post update is now activated * We now use a hash based upon RIPEMD-320 for content and activity * The hash doesn't contain the plink anymore * Legacy item fields are now "null"able * New hash function for a server unique item hash * Introduction of the legacy mode (usage of old item fields) * Code simplification * We don't need the "uri" fields anymore in item-activity and item-content * Use the "created" and not the "received" date for the hash * Avoiding several notices * Some more warnings removed * Improved uri-hash / Likes on Diaspora are now getting a creation date * Corrected the post update version * Ensure an unique uri-hash * Don't delete orhaned item data at the moment * Partly reworked, due to strange behaviour * Some more parts reworked * Using the uri currently seems to be more reliable * Using the uri here as well * Use the hash values again * Grouped item fields in different categories * Notices again * use the gravity (we always should) * Added hint for disabled post updates * Notices ... * Issue #5337: Personal notes are displayed again * Use the gravity again
2018-07-15 20:36:20 +02:00 · 2018-07-15 20:36:20 +02:00 · d3a2ed85fe
parent 8ad6b65aeb
commit d3a2ed85fe
21 changed files with 315 additions and 297 deletions
--- a/boot.php
+++ b/boot.php
@ -41,7 +41,7 @@ define('FRIENDICA_PLATFORM',     'Friendica');
 define('FRIENDICA_CODENAME',     'The Tazmans Flax-lily');
 define('FRIENDICA_VERSION',      '2018.08-dev');
 define('DFRN_PROTOCOL_VERSION',  '2.23');
-define('DB_UPDATE_VERSION',      1276);
+define('DB_UPDATE_VERSION',      1277);
 define('NEW_UPDATE_ROUTINE_VERSION', 1170);

 /**
@ -929,6 +929,10 @@ function remote_user()
 */
 function notice($s)
 {
+	if (empty($_SESSION)) {
+		return;
+	}
+
 	$a = get_app();
 	if (!x($_SESSION, 'sysmsg')) {
 		$_SESSION['sysmsg'] = [];
--- a/database.sql
+++ b/database.sql
@ -1,6 +1,6 @@
 -- ------------------------------------------
 -- Friendica 2018.08-dev (The Tazmans Flax-lily)
-- DB_UPDATE_VERSION 1276
+-- DB_UPDATE_VERSION 1277
 -- ------------------------------------------


@ -455,68 +455,69 @@ CREATE TABLE IF NOT EXISTS `item` (
 	`id` int unsigned NOT NULL auto_increment,
 	`guid` varchar(255) NOT NULL DEFAULT '' COMMENT 'A unique identifier for this item',
 	`uri` varchar(255) NOT NULL DEFAULT '' COMMENT '',
-	`uid` mediumint unsigned NOT NULL DEFAULT 0 COMMENT 'Owner id which owns this copy of the item',
-	`contact-id` int unsigned NOT NULL DEFAULT 0 COMMENT 'contact.id',
-	`type` varchar(20) NOT NULL DEFAULT '' COMMENT '',
-	`wall` boolean NOT NULL DEFAULT '0' COMMENT 'This item was posted to the wall of uid',
-	`gravity` tinyint unsigned NOT NULL DEFAULT 0 COMMENT '',
+	`uri-hash` varchar(80) NOT NULL DEFAULT '' COMMENT 'RIPEMD-128 hash from uri',
 	`parent` int unsigned NOT NULL DEFAULT 0 COMMENT 'item.id of the parent to this item if it is a reply of some form; otherwise this must be set to the id of this item',
 	`parent-uri` varchar(255) NOT NULL DEFAULT '' COMMENT 'uri of the parent to this item',
-	`extid` varchar(255) NOT NULL DEFAULT '' COMMENT '',
 	`thr-parent` varchar(255) NOT NULL DEFAULT '' COMMENT 'If the parent of this item is not the top-level item in the conversation, the uri of the immediate parent; otherwise set to parent-uri',
 	`created` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'Creation timestamp.',
 	`edited` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'Date of last edit (default is created)',
 	`commented` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'Date of last comment/reply to this item',
 	`received` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'datetime',
 	`changed` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'Date that something in the conversation changed, indicating clients should fetch the conversation again',
+	`gravity` tinyint unsigned NOT NULL DEFAULT 0 COMMENT '',
+	`network` char(4) NOT NULL DEFAULT '' COMMENT 'Network from where the item comes from',
 	`owner-id` int unsigned NOT NULL DEFAULT 0 COMMENT 'Link to the contact table with uid=0 of the owner of this item',
-	`owner-name` varchar(255) NOT NULL DEFAULT '' COMMENT 'Name of the owner of this item',
-	`owner-link` varchar(255) NOT NULL DEFAULT '' COMMENT 'Link to the profile page of the owner of this item',
-	`owner-avatar` varchar(255) NOT NULL DEFAULT '' COMMENT 'Link to the avatar picture of the owner of this item',
 	`author-id` int unsigned NOT NULL DEFAULT 0 COMMENT 'Link to the contact table with uid=0 of the author of this item',
-	`author-name` varchar(255) NOT NULL DEFAULT '' COMMENT 'Name of the author of this item',
-	`author-link` varchar(255) NOT NULL DEFAULT '' COMMENT 'Link to the profile page of the author of this item',
-	`author-avatar` varchar(255) NOT NULL DEFAULT '' COMMENT 'Link to the avatar picture of the author of this item',
 	`icid` int unsigned COMMENT 'Id of the item-content table entry that contains the whole item content',
 	`iaid` int unsigned COMMENT 'Id of the item-activity table entry that contains the activity data',
-	`title` varchar(255) NOT NULL DEFAULT '' COMMENT 'item title',
-	`content-warning` varchar(255) NOT NULL DEFAULT '' COMMENT '',
-	`body` mediumtext COMMENT 'item body content',
-	`app` varchar(255) NOT NULL DEFAULT '' COMMENT 'application which generated this item',
-	`verb` varchar(100) NOT NULL DEFAULT '' COMMENT 'ActivityStreams verb',
-	`object-type` varchar(100) NOT NULL DEFAULT '' COMMENT 'ActivityStreams object type',
-	`object` text COMMENT 'JSON encoded object structure unless it is an implied object (normal post)',
-	`target-type` varchar(100) NOT NULL DEFAULT '' COMMENT 'ActivityStreams target type if applicable (URI)',
-	`target` text COMMENT 'JSON encoded target structure if used',
-	`postopts` text COMMENT 'External post connectors add their network name to this comma-separated string to identify that they should be delivered to these networks during delivery',
-	`plink` varchar(255) NOT NULL DEFAULT '' COMMENT 'permalink or URL to a displayable copy of the message at its source',
-	`resource-id` varchar(32) NOT NULL DEFAULT '' COMMENT 'Used to link other tables to items, it identifies the linked resource (e.g. photo) and if set must also set resource_type',
-	`event-id` int unsigned NOT NULL DEFAULT 0 COMMENT 'Used to link to the event.id',
-	`tag` mediumtext COMMENT '',
-	`attach` mediumtext COMMENT 'JSON structure representing attachments to this item',
-	`inform` mediumtext COMMENT '',
-	`file` mediumtext COMMENT '',
-	`location` varchar(255) NOT NULL DEFAULT '' COMMENT 'text location where this item originated',
-	`coord` varchar(255) NOT NULL DEFAULT '' COMMENT 'longitude/latitude pair representing location where this item originated',
+	`extid` varchar(255) NOT NULL DEFAULT '' COMMENT '',
+	`global` boolean NOT NULL DEFAULT '0' COMMENT '',
+	`private` boolean NOT NULL DEFAULT '0' COMMENT 'distribution is restricted',
+	`bookmark` boolean NOT NULL DEFAULT '0' COMMENT 'item has been bookmarked',
+	`visible` boolean NOT NULL DEFAULT '0' COMMENT '',
+	`moderated` boolean NOT NULL DEFAULT '0' COMMENT '',
+	`deleted` boolean NOT NULL DEFAULT '0' COMMENT 'item has been deleted',
+	`uid` mediumint unsigned NOT NULL DEFAULT 0 COMMENT 'Owner id which owns this copy of the item',
+	`contact-id` int unsigned NOT NULL DEFAULT 0 COMMENT 'contact.id',
+	`wall` boolean NOT NULL DEFAULT '0' COMMENT 'This item was posted to the wall of uid',
+	`origin` boolean NOT NULL DEFAULT '0' COMMENT 'item originated at this site',
+	`pubmail` boolean NOT NULL DEFAULT '0' COMMENT '',
+	`starred` boolean NOT NULL DEFAULT '0' COMMENT 'item has been favourited',
+	`unseen` boolean NOT NULL DEFAULT '1' COMMENT 'item has not been seen',
+	`mention` boolean NOT NULL DEFAULT '0' COMMENT 'The owner of this item was mentioned in it',
+	`forum_mode` tinyint unsigned NOT NULL DEFAULT 0 COMMENT '',
 	`allow_cid` mediumtext COMMENT 'Access Control - list of allowed contact.id \'<19><78>\'',
 	`allow_gid` mediumtext COMMENT 'Access Control - list of allowed groups',
 	`deny_cid` mediumtext COMMENT 'Access Control - list of denied contact.id',
 	`deny_gid` mediumtext COMMENT 'Access Control - list of denied groups',
-	`private` boolean NOT NULL DEFAULT '0' COMMENT 'distribution is restricted',
-	`pubmail` boolean NOT NULL DEFAULT '0' COMMENT '',
-	`moderated` boolean NOT NULL DEFAULT '0' COMMENT '',
-	`visible` boolean NOT NULL DEFAULT '0' COMMENT '',
-	`starred` boolean NOT NULL DEFAULT '0' COMMENT 'item has been favourited',
-	`bookmark` boolean NOT NULL DEFAULT '0' COMMENT 'item has been bookmarked',
-	`unseen` boolean NOT NULL DEFAULT '1' COMMENT 'item has not been seen',
-	`deleted` boolean NOT NULL DEFAULT '0' COMMENT 'item has been deleted',
-	`origin` boolean NOT NULL DEFAULT '0' COMMENT 'item originated at this site',
-	`forum_mode` tinyint unsigned NOT NULL DEFAULT 0 COMMENT '',
-	`mention` boolean NOT NULL DEFAULT '0' COMMENT 'The owner of this item was mentioned in it',
-	`network` char(4) NOT NULL DEFAULT '' COMMENT 'Network from where the item comes from',
-	`rendered-hash` varchar(32) NOT NULL DEFAULT '' COMMENT '',
-	`rendered-html` mediumtext COMMENT 'item.body converted to html',
-	`global` boolean NOT NULL DEFAULT '0' COMMENT '',
+	`postopts` text COMMENT 'External post connectors add their network name to this comma-separated string to identify that they should be delivered to these networks during delivery',
+	`inform` mediumtext COMMENT 'Additional receivers of this post',
+	`resource-id` varchar(32) NOT NULL DEFAULT '' COMMENT 'Used to link other tables to items, it identifies the linked resource (e.g. photo) and if set must also set resource_type',
+	`event-id` int unsigned NOT NULL DEFAULT 0 COMMENT 'Used to link to the event.id',
+	`attach` mediumtext COMMENT 'JSON structure representing attachments to this item',
+	`type` varchar(20) NOT NULL DEFAULT '' COMMENT '',
+	`file` mediumtext COMMENT 'Deprecated',
+	`location` varchar(255) COMMENT 'Deprecated',
+	`coord` varchar(255) COMMENT 'Deprecated',
+	`tag` mediumtext COMMENT 'Deprecated',
+	`plink` varchar(255) COMMENT 'Deprecated',
+	`title` varchar(255) COMMENT 'Deprecated',
+	`content-warning` varchar(255) COMMENT 'Deprecated',
+	`body` mediumtext COMMENT 'Deprecated',
+	`app` varchar(255) COMMENT 'Deprecated',
+	`verb` varchar(100) COMMENT 'Deprecated',
+	`object-type` varchar(100) COMMENT 'Deprecated',
+	`object` text COMMENT 'Deprecated',
+	`target-type` varchar(100) COMMENT 'Deprecated',
+	`target` text COMMENT 'Deprecated',
+	`author-name` varchar(255) COMMENT 'Deprecated',
+	`author-link` varchar(255) COMMENT 'Deprecated',
+	`author-avatar` varchar(255) COMMENT 'Deprecated',
+	`owner-name` varchar(255) COMMENT 'Deprecated',
+	`owner-link` varchar(255) COMMENT 'Deprecated',
+	`owner-avatar` varchar(255) COMMENT 'Deprecated',
+	`rendered-hash` varchar(32) COMMENT 'Deprecated',
+	`rendered-html` mediumtext COMMENT 'Deprecated',
 	 PRIMARY KEY(`id`),
 	 INDEX `guid` (`guid`(191)),
 	 INDEX `uri` (`uri`(191)),
@ -549,8 +550,8 @@ CREATE TABLE IF NOT EXISTS `item` (
 --
 CREATE TABLE IF NOT EXISTS `item-activity` (
 	`id` int unsigned NOT NULL auto_increment,
-	`uri` varchar(255) NOT NULL DEFAULT '' COMMENT '',
-	`uri-hash` char(80) NOT NULL DEFAULT '' COMMENT 'SHA-1 and RIPEMD-160 hash from uri',
+	`uri` varchar(255) COMMENT '',
+	`uri-hash` varchar(80) NOT NULL DEFAULT '' COMMENT 'RIPEMD-128 hash from uri',
 	`activity` smallint unsigned NOT NULL DEFAULT 0 COMMENT '',
 	 PRIMARY KEY(`id`),
 	 UNIQUE INDEX `uri-hash` (`uri-hash`),
@ -562,8 +563,8 @@ CREATE TABLE IF NOT EXISTS `item-activity` (
 --
 CREATE TABLE IF NOT EXISTS `item-content` (
 	`id` int unsigned NOT NULL auto_increment,
-	`uri` varchar(255) NOT NULL DEFAULT '' COMMENT '',
-	`uri-plink-hash` char(80) NOT NULL DEFAULT '' COMMENT 'SHA-1 hash from uri and plink',
+	`uri` varchar(255) COMMENT '',
+	`uri-plink-hash` varchar(80) NOT NULL DEFAULT '' COMMENT 'RIPEMD-128 hash from uri',
 	`title` varchar(255) NOT NULL DEFAULT '' COMMENT 'item title',
 	`content-warning` varchar(255) NOT NULL DEFAULT '' COMMENT '',
 	`body` mediumtext COMMENT 'item body content',
@ -591,8 +592,8 @@ CREATE TABLE IF NOT EXISTS `locks` (
 	`id` int unsigned NOT NULL auto_increment COMMENT 'sequential ID',
 	`name` varchar(128) NOT NULL DEFAULT '' COMMENT '',
 	`locked` boolean NOT NULL DEFAULT '0' COMMENT '',
-	`expires` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'datetime of lock expiration',
 	`pid` int unsigned NOT NULL DEFAULT 0 COMMENT 'Process ID',
+	`expires` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'datetime of cache expiration',
 	 PRIMARY KEY(`id`),
 	 INDEX `name_expires` (`name`,`expires`)
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='';
--- a/mod/friendica.php
+++ b/mod/friendica.php
@ -42,7 +42,7 @@ function friendica_init(App $a)

 		Config::load('feature_lock');
 		$locked_features = [];
-		if (is_array($a->config['feature_lock']) && count($a->config['feature_lock'])) {
+		if (!empty($a->config['feature_lock']) && count($a->config['feature_lock'])) {
 			foreach ($a->config['feature_lock'] as $k => $v) {
 				if ($k === 'config_loaded') {
 					continue;
--- a/mod/notes.php
+++ b/mod/notes.php
@ -57,9 +57,9 @@ function notes_content(App $a, $update = false)
 		$o .= status_editor($a, $x, $a->contact['id']);
 	}

-	$condition = ["`uid` = ? AND `type` = 'note' AND `id` = `parent` AND NOT `wall`
+	$condition = ["`uid` = ? AND `type` = 'note' AND `gravity` = ? AND NOT `wall`
 		AND `allow_cid` = ? AND `contact-id` = ?",
-		local_user(), '<' . $a->contact['id'] . '>', $a->contact['id']];
+		local_user(), GRAVITY_PARENT, '<' . $a->contact['id'] . '>', $a->contact['id']];

 	$notes = dba::count('item', $condition);

@ -68,13 +68,13 @@ function notes_content(App $a, $update = false)

 	$params = ['order' => ['created' => true],
 		'limit' => [$a->pager['start'], $a->pager['itemspage']]];
-	$r = Item::selectForUser(local_user(), ['item_id'], $condition, $params);
+	$r = Item::selectForUser(local_user(), ['id'], $condition, $params);

 	if (DBM::is_result($r)) {
 		$parents_arr = [];

 		while ($rr = Item::fetch($r)) {
-			$parents_arr[] = $rr['item_id'];
+			$parents_arr[] = $rr['id'];
 		}
 		dba::close($r);

--- a/mod/parse_url.php
+++ b/mod/parse_url.php
@ -67,9 +67,12 @@ function parse_url_content(App $a) {
 		$hdrs = [];
 		$h = explode("\n", $result["header"]);
 		foreach ($h as $l) {
-			list($k,$v) = array_map("trim", explode(":", trim($l), 2));
+			$header = array_map("trim", explode(":", trim($l), 2));
+			if (count($header) == 2) {
+				list($k,$v) = $header;
 				$hdrs[$k] = $v;
 			}
+		}
 		if (array_key_exists("Content-Type", $hdrs)) {
 			$type = $hdrs["Content-Type"];
 		}
--- a/mod/settings.php
+++ b/mod/settings.php
@ -26,12 +26,14 @@ use Friendica\Util\Temporal;
 function get_theme_config_file($theme)
 {
 	$a = get_app();
+	if (!empty($a->theme_info['extends'])) {
 		$base_theme = $a->theme_info['extends'];
+	}

 	if (file_exists("view/theme/$theme/config.php")) {
 		return "view/theme/$theme/config.php";
 	}
-	if (file_exists("view/theme/$base_theme/config.php")) {
+	if (!empty($base_theme) && file_exists("view/theme/$base_theme/config.php")) {
 		return "view/theme/$base_theme/config.php";
 	}
 	return null;
@ -1155,7 +1157,7 @@ function settings_content(App $a)

 	// Private/public post links for the non-JS ACL form
 	$private_post = 1;
-	if ($_REQUEST['public']) {
+	if (!empty($_REQUEST['public']) && !$_REQUEST['public']) {
 		$private_post = 0;
 	}

--- a/src/Content/Text/BBCode.php
+++ b/src/Content/Text/BBCode.php
@ -579,7 +579,7 @@ class BBCode extends BaseObject
 					$return .= sprintf('<a href="%s" target="_blank"><img src="%s" alt="" title="%s" class="attachment-preview" /></a><br />', $data["url"], self::proxyUrl($data["preview"], $simplehtml), $data["title"]);
 				}

-				if (($data["type"] == "photo") && ($data["url"] != "") && ($data["image"] != "")) {
+				if (($data["type"] == "photo") && !empty($data["url"]) && !empty($data["image"])) {
 					$return .= sprintf('<a href="%s" target="_blank"><img src="%s" alt="" title="%s" class="attachment-image" /></a>', $data["url"], self::proxyUrl($data["image"], $simplehtml), $data["title"]);
 				} else {
 					$return .= sprintf('<h4><a href="%s">%s</a></h4>', $data['url'], $data['title']);
@ -613,7 +613,7 @@ class BBCode extends BaseObject
 			return $data["text"] . $data["after"];
 		}

-		$title = htmlentities($data["title"], ENT_QUOTES, 'UTF-8', false);
+		$title = htmlentities(defaults($data, 'title', ''), ENT_QUOTES, 'UTF-8', false);
 		$text = htmlentities($data["text"], ENT_QUOTES, 'UTF-8', false);
 		if ($plaintext || (($title != "") && strstr($text, $title))) {
 			$data["title"] = $data["url"];
--- a/src/Core/System.php
+++ b/src/Core/System.php
@ -212,7 +212,10 @@ EOT;
 	 */
 	public static function processID($prefix)
 	{
-		return uniqid($prefix . ':' . str_pad(getmypid() . ':', 8, '0') . ':');
+		// We aren't calling any other function here.
+		// Doing so could easily create an endless loop
+		$trailer = $prefix . ':' . getmypid() . ':';
+		return substr($trailer . uniqid('') . mt_rand(), 0, 26);
 	}

 	/// @todo Move the following functions from boot.php
--- a/src/Core/Worker.php
+++ b/src/Core/Worker.php
@ -352,7 +352,7 @@ class Worker
 		$a->process_id = $old_process_id;
 		unset($a->queue);

-		$duration = number_format(microtime(true) - $stamp, 3);
+		$duration = (microtime(true) - $stamp);

 		self::$up_start = microtime(true);

--- a/src/Database/DBStructure.php
+++ b/src/Database/DBStructure.php
@ -536,26 +536,26 @@ class DBStructure
 	private static function FieldCommand($parameters, $create = true) {
 		$fieldstruct = $parameters["type"];

-		if (!empty($parameters["Collation"])) {
+		if (isset($parameters["Collation"])) {
 			$fieldstruct .= " COLLATE ".$parameters["Collation"];
 		}

-		if (!empty($parameters["not null"])) {
+		if (isset($parameters["not null"])) {
 			$fieldstruct .= " NOT NULL";
 		}

-		if (!empty($parameters["default"])) {
+		if (isset($parameters["default"])) {
 			if (strpos(strtolower($parameters["type"]),"int")!==false) {
 				$fieldstruct .= " DEFAULT ".$parameters["default"];
 			} else {
 				$fieldstruct .= " DEFAULT '".$parameters["default"]."'";
 			}
 		}
-		if (!empty($parameters["extra"])) {
+		if (isset($parameters["extra"])) {
 			$fieldstruct .= " ".$parameters["extra"];
 		}

-		if (!empty($parameters["comment"])) {
+		if (isset($parameters["comment"])) {
 			$fieldstruct .= " COMMENT '".dbesc($parameters["comment"])."'";
 		}

@ -588,11 +588,11 @@ class DBStructure
 			}
 		}

-		if (!empty($structure["engine"])) {
+		if (isset($structure["engine"])) {
 			$engine = " ENGINE=" . $structure["engine"];
 		}

-		if (!empty($structure["comment"])) {
+		if (isset($structure["comment"])) {
 			$comment = " COMMENT='" . dbesc($structure["comment"]) . "'";
 		}

@ -1158,68 +1158,76 @@ class DBStructure
 						"id" => ["type" => "int unsigned", "not null" => "1", "extra" => "auto_increment", "primary" => "1", "relation" => ["thread" => "iid"]],
 						"guid" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "A unique identifier for this item"],
 						"uri" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => ""],
-						"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "relation" => ["user" => "uid"], "comment" => "Owner id which owns this copy of the item"],
-						"contact-id" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "relation" => ["contact" => "id"], "comment" => "contact.id"],
-						"type" => ["type" => "varchar(20)", "not null" => "1", "default" => "", "comment" => ""],
-						"wall" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "This item was posted to the wall of uid"],
-						"gravity" => ["type" => "tinyint unsigned", "not null" => "1", "default" => "0", "comment" => ""],
+						"uri-hash" => ["type" => "varchar(80)", "not null" => "1", "default" => "", "comment" => "RIPEMD-128 hash from uri"],
 						"parent" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "relation" => ["item" => "id"], "comment" => "item.id of the parent to this item if it is a reply of some form; otherwise this must be set to the id of this item"],
 						"parent-uri" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "uri of the parent to this item"],
-						"extid" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => ""],
 						"thr-parent" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "If the parent of this item is not the top-level item in the conversation, the uri of the immediate parent; otherwise set to parent-uri"],
 						"created" => ["type" => "datetime", "not null" => "1", "default" => NULL_DATE, "comment" => "Creation timestamp."],
 						"edited" => ["type" => "datetime", "not null" => "1", "default" => NULL_DATE, "comment" => "Date of last edit (default is created)"],
 						"commented" => ["type" => "datetime", "not null" => "1", "default" => NULL_DATE, "comment" => "Date of last comment/reply to this item"],
 						"received" => ["type" => "datetime", "not null" => "1", "default" => NULL_DATE, "comment" => "datetime"],
 						"changed" => ["type" => "datetime", "not null" => "1", "default" => NULL_DATE, "comment" => "Date that something in the conversation changed, indicating clients should fetch the conversation again"],
+						"gravity" => ["type" => "tinyint unsigned", "not null" => "1", "default" => "0", "comment" => ""],
+						"network" => ["type" => "char(4)", "not null" => "1", "default" => "", "comment" => "Network from where the item comes from"],
 						"owner-id" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "relation" => ["contact" => "id"], "comment" => "Link to the contact table with uid=0 of the owner of this item"],
-						"owner-name" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "Name of the owner of this item"],
-						"owner-link" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "Link to the profile page of the owner of this item"],
-						"owner-avatar" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "Link to the avatar picture of the owner of this item"],
 						"author-id" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "relation" => ["contact" => "id"], "comment" => "Link to the contact table with uid=0 of the author of this item"],
-						"author-name" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "Name of the author of this item"],
-						"author-link" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "Link to the profile page of the author of this item"],
-						"author-avatar" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "Link to the avatar picture of the author of this item"],
 						"icid" => ["type" => "int unsigned", "relation" => ["item-content" => "id"], "comment" => "Id of the item-content table entry that contains the whole item content"],
 						"iaid" => ["type" => "int unsigned", "relation" => ["item-activity" => "id"], "comment" => "Id of the item-activity table entry that contains the activity data"],
-						"title" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "item title"],
-						"content-warning" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => ""],
-						"body" => ["type" => "mediumtext", "comment" => "item body content"],
-						"app" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "application which generated this item"],
-						"verb" => ["type" => "varchar(100)", "not null" => "1", "default" => "", "comment" => "ActivityStreams verb"],
-						"object-type" => ["type" => "varchar(100)", "not null" => "1", "default" => "", "comment" => "ActivityStreams object type"],
-						"object" => ["type" => "text", "comment" => "JSON encoded object structure unless it is an implied object (normal post)"],
-						"target-type" => ["type" => "varchar(100)", "not null" => "1", "default" => "", "comment" => "ActivityStreams target type if applicable (URI)"],
-						"target" => ["type" => "text", "comment" => "JSON encoded target structure if used"],
-						"postopts" => ["type" => "text", "comment" => "External post connectors add their network name to this comma-separated string to identify that they should be delivered to these networks during delivery"],
-						"plink" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "permalink or URL to a displayable copy of the message at its source"],
-						"resource-id" => ["type" => "varchar(32)", "not null" => "1", "default" => "", "comment" => "Used to link other tables to items, it identifies the linked resource (e.g. photo) and if set must also set resource_type"],
-						"event-id" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "relation" => ["event" => "id"], "comment" => "Used to link to the event.id"],
-						"tag" => ["type" => "mediumtext", "comment" => ""],
-						"attach" => ["type" => "mediumtext", "comment" => "JSON structure representing attachments to this item"],
-						"inform" => ["type" => "mediumtext", "comment" => ""],
-						"file" => ["type" => "mediumtext", "comment" => ""],
-						"location" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "text location where this item originated"],
-						"coord" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "longitude/latitude pair representing location where this item originated"],
+						"extid" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => ""],
+						"global" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
+						"private" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "distribution is restricted"],
+						"bookmark" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "item has been bookmarked"],
+						"visible" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
+						"moderated" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
+						"deleted" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "item has been deleted"],
+						// User specific fields. Eventually they will move to user-item
+						"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "relation" => ["user" => "uid"], "comment" => "Owner id which owns this copy of the item"],
+						"contact-id" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "relation" => ["contact" => "id"], "comment" => "contact.id"],
+						"wall" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "This item was posted to the wall of uid"],
+						"origin" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "item originated at this site"],
+						"pubmail" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
+						"starred" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "item has been favourited"],
+						"unseen" => ["type" => "boolean", "not null" => "1", "default" => "1", "comment" => "item has not been seen"],
+						"mention" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "The owner of this item was mentioned in it"],
+						"forum_mode" => ["type" => "tinyint unsigned", "not null" => "1", "default" => "0", "comment" => ""],
+						// User specific fields. Should possible be replaced with something different
 						"allow_cid" => ["type" => "mediumtext", "comment" => "Access Control - list of allowed contact.id '<19><78>'"],
 						"allow_gid" => ["type" => "mediumtext", "comment" => "Access Control - list of allowed groups"],
 						"deny_cid" => ["type" => "mediumtext", "comment" => "Access Control - list of denied contact.id"],
 						"deny_gid" => ["type" => "mediumtext", "comment" => "Access Control - list of denied groups"],
-						"private" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "distribution is restricted"],
-						"pubmail" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
-						"moderated" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
-						"visible" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
-						"starred" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "item has been favourited"],
-						"bookmark" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "item has been bookmarked"],
-						"unseen" => ["type" => "boolean", "not null" => "1", "default" => "1", "comment" => "item has not been seen"],
-						"deleted" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "item has been deleted"],
-						"origin" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "item originated at this site"],
-						"forum_mode" => ["type" => "tinyint unsigned", "not null" => "1", "default" => "0", "comment" => ""],
-						"mention" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "The owner of this item was mentioned in it"],
-						"network" => ["type" => "char(4)", "not null" => "1", "default" => "", "comment" => "Network from where the item comes from"],
-						"rendered-hash" => ["type" => "varchar(32)", "not null" => "1", "default" => "", "comment" => ""],
-						"rendered-html" => ["type" => "mediumtext", "comment" => "item.body converted to html"],
-						"global" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
+						"postopts" => ["type" => "text", "comment" => "External post connectors add their network name to this comma-separated string to identify that they should be delivered to these networks during delivery"],
+						"inform" => ["type" => "mediumtext", "comment" => "Additional receivers of this post"],
+						// It is to be decided whether these fields belong to the user or the structure
+						"resource-id" => ["type" => "varchar(32)", "not null" => "1", "default" => "", "comment" => "Used to link other tables to items, it identifies the linked resource (e.g. photo) and if set must also set resource_type"],
+						"event-id" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "relation" => ["event" => "id"], "comment" => "Used to link to the event.id"],
+						// Will be replaced by the "attach" table
+						"attach" => ["type" => "mediumtext", "comment" => "JSON structure representing attachments to this item"],
+						// Seems to be only used for notes, but is filled at many places.
+						// Will be replaced with some general field that contain the values of "origin" and "wall" as well.
+						"type" => ["type" => "varchar(20)", "not null" => "1", "default" => "", "comment" => ""],
+						// Deprecated fields. Will be removed in upcoming versions
+						"file" => ["type" => "mediumtext", "comment" => "Deprecated"],
+						"location" => ["type" => "varchar(255)", "comment" => "Deprecated"],
+						"coord" => ["type" => "varchar(255)", "comment" => "Deprecated"],
+						"tag" => ["type" => "mediumtext", "comment" => "Deprecated"],
+						"plink" => ["type" => "varchar(255)", "comment" => "Deprecated"],
+						"title" => ["type" => "varchar(255)", "comment" => "Deprecated"],
+						"content-warning" => ["type" => "varchar(255)", "comment" => "Deprecated"],
+						"body" => ["type" => "mediumtext", "comment" => "Deprecated"],
+						"app" => ["type" => "varchar(255)", "comment" => "Deprecated"],
+						"verb" => ["type" => "varchar(100)", "comment" => "Deprecated"],
+						"object-type" => ["type" => "varchar(100)", "comment" => "Deprecated"],
+						"object" => ["type" => "text", "comment" => "Deprecated"],
+						"target-type" => ["type" => "varchar(100)", "comment" => "Deprecated"],
+						"target" => ["type" => "text", "comment" => "Deprecated"],
+						"author-name" => ["type" => "varchar(255)", "comment" => "Deprecated"],
+						"author-link" => ["type" => "varchar(255)", "comment" => "Deprecated"],
+						"author-avatar" => ["type" => "varchar(255)", "comment" => "Deprecated"],
+						"owner-name" => ["type" => "varchar(255)", "comment" => "Deprecated"],
+						"owner-link" => ["type" => "varchar(255)", "comment" => "Deprecated"],
+						"owner-avatar" => ["type" => "varchar(255)", "comment" => "Deprecated"],
+						"rendered-hash" => ["type" => "varchar(32)", "comment" => "Deprecated"],
+						"rendered-html" => ["type" => "mediumtext", "comment" => "Deprecated"],
 						],
 				"indexes" => [
 						"PRIMARY" => ["id"],
@ -1253,8 +1261,8 @@ class DBStructure
 				"comment" => "Activities for items",
 				"fields" => [
 						"id" => ["type" => "int unsigned", "not null" => "1", "extra" => "auto_increment", "primary" => "1", "relation" => ["thread" => "iid"]],
-						"uri" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => ""],
-						"uri-hash" => ["type" => "char(80)", "not null" => "1", "default" => "", "comment" => "SHA-1 and RIPEMD-160 hash from uri"],
+						"uri" => ["type" => "varchar(255)", "comment" => ""],
+						"uri-hash" => ["type" => "varchar(80)", "not null" => "1", "default" => "", "comment" => "RIPEMD-128 hash from uri"],
 						"activity" => ["type" => "smallint unsigned", "not null" => "1", "default" => "0", "comment" => ""],
 						],
 				"indexes" => [
@ -1267,8 +1275,8 @@ class DBStructure
 				"comment" => "Content for all posts",
 				"fields" => [
 						"id" => ["type" => "int unsigned", "not null" => "1", "extra" => "auto_increment", "primary" => "1", "relation" => ["thread" => "iid"]],
-						"uri" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => ""],
-						"uri-plink-hash" => ["type" => "char(80)", "not null" => "1", "default" => "", "comment" => "SHA-1 hash from uri and plink"],
+						"uri" => ["type" => "varchar(255)", "comment" => ""],
+						"uri-plink-hash" => ["type" => "varchar(80)", "not null" => "1", "default" => "", "comment" => "RIPEMD-128 hash from uri"],
 						"title" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "item title"],
 						"content-warning" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => ""],
 						"body" => ["type" => "mediumtext", "comment" => "item body content"],
--- a/src/Database/PostUpdate.php
+++ b/src/Database/PostUpdate.php
@ -31,10 +31,7 @@ class PostUpdate
 		if (!self::update1206()) {
 			return;
 		}
-		if (!self::update1274()) {
-			return;
-		}
-		if (!self::update1275()) {
+		if (!self::update1276()) {
 			return;
 		}
 	}
@ -226,95 +223,62 @@ class PostUpdate
 	}

 	/**
-	 * @brief update the "item-content" table
+	 * @brief update the item related tables
 	 *
 	 * @return bool "true" when the job is done
 	 */
-	private static function update1274()
+	private static function update1276()
 	{
 		// Was the script completed?
-		if (Config::get("system", "post_update_version") >= 1274) {
+		if (Config::get("system", "post_update_version") >= 1276) {
 			return true;
 		}

-		logger("Start", LOGGER_DEBUG);
+		$id = Config::get("system", "post_update_version_1276_id", 0);

-		$fields = ['id', 'title', 'content-warning', 'body', 'location', 'tag', 'file',
-			'coord', 'app', 'rendered-hash', 'rendered-html', 'verb',
-			'object-type', 'object', 'target-type', 'target', 'plink',
-			'author-id', 'owner-id'];
+		logger("Start from item " . $id, LOGGER_DEBUG);

-		$condition = ["`icid` IS NULL"];
-		$params = ['limit' => 10000];
-		$items = Item::select($fields, $condition, $params);
-
-		if (!DBM::is_result($items)) {
-			Config::set("system", "post_update_version", 1274);
-			logger("Done", LOGGER_DEBUG);
-			return true;
-		}
+		$fields = array_merge(Item::MIXED_CONTENT_FIELDLIST, ['network', 'author-id', 'owner-id', 'tag', 'file',
+			'author-name', 'author-avatar', 'author-link', 'owner-name', 'owner-avatar', 'owner-link', 'id']);

+		$start_id = $id;
 		$rows = 0;
-
+		$condition = ["`id` > ?", $id];
+		$params = ['order' => ['id'], 'limit' => 10000];
+		$items = Item::select($fields, $condition, $params);
 		while ($item = Item::fetch($items)) {
-			// Clearing the author and owner data if there is an id.
-			if ($item['author-id'] > 0) {
-				$item['author-name'] = '';
-				$item['author-link'] = '';
-				$item['author-avatar'] = '';
+			$id = $item['id'];
+
+			if (empty($item['author-id'])) {
+				$default = ['url' => $item['author-link'], 'name' => $item['author-name'],
+					'photo' => $item['author-avatar'], 'network' => $item['network']];
+
+				$item['author-id'] = Contact::getIdForURL($item["author-link"], 0, false, $default);
 			}

-			if ($item['owner-id'] > 0) {
-				$item['owner-name'] = '';
-				$item['owner-link'] = '';
-				$item['owner-avatar'] = '';
+			if (empty($item['owner-id'])) {
+				$default = ['url' => $item['owner-link'], 'name' => $item['owner-name'],
+					'photo' => $item['owner-avatar'], 'network' => $item['network']];
+
+				$item['owner-id'] = Contact::getIdForURL($item["owner-link"], 0, false, $default);
 			}

-			Item::update($item, ['id' => $item['id']]);
+			Item::update($item, ['id' => $id]);
+
 			++$rows;
 		}
 		dba::close($items);

-		logger("Processed rows: " . $rows, LOGGER_DEBUG);
-		return true;
-	}
-	/**
-	 * @brief update the "item-activity" table
-	 *
-	 * @return bool "true" when the job is done
-	 */
-	private static function update1275()
-	{
-		// Was the script completed?
-		if (Config::get("system", "post_update_version") >= 1275) {
-			return true;
-		}
+		Config::set("system", "post_update_version_1276_id", $id);

-		logger("Start", LOGGER_DEBUG);
+		logger("Processed rows: " . $rows . " - last processed item:  " . $id, LOGGER_DEBUG);

-		$fields = ['id', 'verb'];
-
-		$condition = ["`iaid` IS NULL AND NOT `icid` IS NULL AND `verb` IN (?, ?, ?, ?, ?)",
-			ACTIVITY_LIKE, ACTIVITY_DISLIKE, ACTIVITY_ATTEND, ACTIVITY_ATTENDNO, ACTIVITY_ATTENDMAYBE];
-
-		$params = ['limit' => 10000];
-		$items = Item::select($fields, $condition, $params);
-
-		if (!DBM::is_result($items)) {
-			Config::set("system", "post_update_version", 1275);
+		if ($start_id == $id) {
+			Config::set("system", "post_update_version", 1276);
 			logger("Done", LOGGER_DEBUG);
 			return true;
 		}

-		$rows = 0;
-
-		while ($item = Item::fetch($items)) {
-			Item::update($item, ['id' => $item['id']]);
-			++$rows;
-		}
-		dba::close($items);
-
-		logger("Processed rows: " . $rows, LOGGER_DEBUG);
-		return true;
+		return false;
 	}
 }
--- a/src/Model/Item.php
+++ b/src/Model/Item.php
@ -78,6 +78,17 @@ class Item extends BaseObject
 	// The item-activity table only stores the index and needs this array to know the matching activity.
 	const ACTIVITIES = [ACTIVITY_LIKE, ACTIVITY_DISLIKE, ACTIVITY_ATTEND, ACTIVITY_ATTENDNO, ACTIVITY_ATTENDMAYBE];

+	private static $legacy_mode = null;
+
+	public static function isLegacyMode()
+	{
+		if (is_null(self::$legacy_mode)) {
+			self::$legacy_mode = (Config::get("system", "post_update_version") < 1276);
+		}
+
+		return self::$legacy_mode;
+	}
+
 	/**
 	 * @brief returns an activity index from an activity string
 	 *
@ -156,12 +167,14 @@ class Item extends BaseObject
 		// ---------------------- Transform item content data ----------------------

 		// Fetch data from the item-content table whenever there is content there
+		if (self::isLegacyMode()) {
 			foreach (self::MIXED_CONTENT_FIELDLIST as $field) {
 				if (empty($row[$field]) && !empty($row['internal-item-' . $field])) {
 					$row[$field] = $row['internal-item-' . $field];
 				}
 				unset($row['internal-item-' . $field]);
 			}
+		}

 		if (!empty($row['internal-iaid']) && array_key_exists('verb', $row)) {
 			$row['verb'] = self::indexToActivity($row['internal-activity']);
@ -568,20 +581,20 @@ class Item extends BaseObject
 			$joins .= sprintf("STRAIGHT_JOIN `contact` ON `contact`.`id` = $master_table.`contact-id`
 				AND NOT `contact`.`blocked`
 				AND ((NOT `contact`.`readonly` AND NOT `contact`.`pending` AND (`contact`.`rel` IN (%s, %s)))
-				OR `contact`.`self` OR (`item`.`id` != `item`.`parent`) OR `contact`.`uid` = 0)
+				OR `contact`.`self` OR `item`.`gravity` != %d OR `contact`.`uid` = 0)
 				STRAIGHT_JOIN `contact` AS `author` ON `author`.`id` = $master_table.`author-id` AND NOT `author`.`blocked`
 				STRAIGHT_JOIN `contact` AS `owner` ON `owner`.`id` = $master_table.`owner-id` AND NOT `owner`.`blocked`
 				LEFT JOIN `user-item` ON `user-item`.`iid` = $master_table_key AND `user-item`.`uid` = %d",
-				CONTACT_IS_SHARING, CONTACT_IS_FRIEND, intval($uid));
+				CONTACT_IS_SHARING, CONTACT_IS_FRIEND, GRAVITY_PARENT, intval($uid));
 		} else {
 			if (strpos($sql_commands, "`contact`.") !== false) {
-				$joins .= "STRAIGHT_JOIN `contact` ON `contact`.`id` = $master_table.`contact-id`";
+				$joins .= "LEFT JOIN `contact` ON `contact`.`id` = $master_table.`contact-id`";
 			}
 			if (strpos($sql_commands, "`author`.") !== false) {
-				$joins .= " STRAIGHT_JOIN `contact` AS `author` ON `author`.`id` = $master_table.`author-id`";
+				$joins .= " LEFT JOIN `contact` AS `author` ON `author`.`id` = $master_table.`author-id`";
 			}
 			if (strpos($sql_commands, "`owner`.") !== false) {
-				$joins .= " STRAIGHT_JOIN `contact` AS `owner` ON `owner`.`id` = $master_table.`owner-id`";
+				$joins .= " LEFT JOIN `contact` AS `owner` ON `owner`.`id` = $master_table.`owner-id`";
 			}
 		}

@ -645,7 +658,7 @@ class Item extends BaseObject
 		foreach ($fields as $table => $table_fields) {
 			foreach ($table_fields as $field => $select) {
 				if (empty($selected) || in_array($select, $selected)) {
-					if (in_array($select, self::MIXED_CONTENT_FIELDLIST)) {
+					if (self::isLegacyMode() && in_array($select, self::MIXED_CONTENT_FIELDLIST)) {
 						$selection[] = "`item`.`".$select."` AS `internal-item-" . $select . "`";
 					}
 					if (is_int($field)) {
@ -685,6 +698,19 @@ class Item extends BaseObject
 		return $query;
 	}

+	/**
+	 * @brief Generate a server unique item hash for linking between the item tables
+	 *
+	 * @param string $uri     Item URI
+	 * @param date   $created Item creation date
+	 *
+	 * @return string the item hash
+	 */
+	private static function itemHash($uri, $created)
+	{
+		return round(strtotime($created) / 100) . hash('ripemd128', $uri);
+	}
+
 	/**
 	 * @brief Update existing item entries
 	 *
@ -710,13 +736,13 @@ class Item extends BaseObject
 		// We cannot simply expand the condition to check for origin entries
 		// The condition needn't to be a simple array but could be a complex condition.
 		// And we have to execute this query before the update to ensure to fetch the same data.
-		$items = dba::select('item', ['id', 'origin', 'uri', 'plink', 'iaid', 'icid', 'tag', 'file'], $condition);
+		$items = dba::select('item', ['id', 'origin', 'uri', 'created', 'uri-hash', 'iaid', 'icid', 'tag', 'file'], $condition);

 		$content_fields = [];
 		foreach (array_merge(self::CONTENT_FIELDLIST, self::MIXED_CONTENT_FIELDLIST) as $field) {
 			if (isset($fields[$field])) {
 				$content_fields[$field] = $fields[$field];
-				if (in_array($field, self::CONTENT_FIELDLIST)) {
+				if (in_array($field, self::CONTENT_FIELDLIST) || !self::isLegacyMode()) {
 					unset($fields[$field]);
 				} else {
 					$fields[$field] = null;
@ -759,18 +785,41 @@ class Item extends BaseObject
 		$rows = dba::affected_rows();

 		while ($item = dba::fetch($items)) {
-			if (!empty($item['plink'])) {
-				$content_fields['plink'] = $item['plink'];
+			// This part here can safely be removed when the legacy fields in the item had been removed
+			if (empty($item['uri-hash']) && !empty($item['uri']) && !empty($item['created'])) {
+
+				// Fetch the uri-hash from an existing item entry if there is one
+				$item_condition = ["`uri` = ? AND `uri-hash` != ''", $item['uri']];
+				$existing = dba::selectfirst('item', ['uri-hash'], $item_condition);
+				if (DBM::is_result($existing)) {
+					$item['uri-hash'] = $existing['uri-hash'];
+				} else {
+					$item['uri-hash'] = self::itemHash($item['uri'], $item['created']);
 				}
+
+				dba::update('item', ['uri-hash' => $item['uri-hash']], ['id' => $item['id']]);
+				dba::update('item-activity', ['uri-hash' => $item['uri-hash']], ["`uri` = ? AND `uri-hash` = ''", $item['uri']]);
+				dba::update('item-content', ['uri-plink-hash' => $item['uri-hash']], ["`uri` = ? AND `uri-plink-hash` = ''", $item['uri']]);
+			}
+
 			if (!empty($item['iaid']) || (!empty($content_fields['verb']) && (self::activityToIndex($content_fields['verb']) >= 0))) {
-				self::updateActivity($content_fields, ['uri' => $item['uri']]);
+				if (!empty($item['iaid'])) {
+					$update_condition = ['id' => $item['iaid']];
+				} else {
+					$update_condition = ['uri-hash' => $item['uri-hash']];
+				}
+				self::updateActivity($content_fields, $update_condition);

 				if (empty($item['iaid'])) {
-					$item_activity = dba::selectFirst('item-activity', ['id'], ['uri' => $item['uri']]);
+					$item_activity = dba::selectFirst('item-activity', ['id'], ['uri-hash' => $item['uri-hash']]);
 					if (DBM::is_result($item_activity)) {
 						$item_fields = ['iaid' => $item_activity['id'], 'icid' => null];
 						foreach (self::MIXED_CONTENT_FIELDLIST as $field) {
-							$item_fields[$field] = '';
+							if (self::isLegacyMode()) {
+								$item_fields[$field] = null;
+							} else {
+								unset($item_fields[$field]);
+							}
 						}
 						dba::update('item', $item_fields, ['id' => $item['id']]);

@ -786,16 +835,25 @@ class Item extends BaseObject
 					}
 				}
 			} else {
-				self::updateContent($content_fields, ['uri' => $item['uri']]);
+				if (!empty($item['icid'])) {
+					$update_condition = ['id' => $item['icid']];
+				} else {
+					$update_condition = ['uri-plink-hash' => $item['uri-hash']];
+				}
+				self::updateContent($content_fields, $update_condition);

 				if (empty($item['icid'])) {
-					$item_content = dba::selectFirst('item-content', [], ['uri' => $item['uri']]);
+					$item_content = dba::selectFirst('item-content', [], ['uri-plink-hash' => $item['uri-hash']]);
 					if (DBM::is_result($item_content)) {
 						$item_fields = ['icid' => $item_content['id']];
 						// Clear all fields in the item table that have a content in the item-content table
 						foreach ($item_content as $field => $content) {
 							if (in_array($field, self::MIXED_CONTENT_FIELDLIST) && !empty($item_content[$field])) {
-								$item_fields[$field] = '';
+								if (self::isLegacyMode()) {
+									$item_fields[$field] = null;
+								} else {
+									unset($item_fields[$field]);
+								}
 							}
 						}
 						dba::update('item', $item_fields, ['id' => $item['id']]);
@ -1228,6 +1286,13 @@ class Item extends BaseObject
 			}
 		}

+		// Ensure to always have the same creation date.
+		$existing = dba::selectfirst('item', ['created', 'uri-hash'], ['uri' => $item['uri']]);
+		if (DBM::is_result($existing)) {
+			$item['created'] = $existing['created'];
+			$item['uri-hash'] = $existing['uri-hash'];
+		}
+
 		self::addLanguageToItemArray($item);

 		$item['wall']          = intval(defaults($item, 'wall', 0));
@ -1272,6 +1337,9 @@ class Item extends BaseObject
 		$item['inform']        = trim(defaults($item, 'inform', ''));
 		$item['file']          = trim(defaults($item, 'file', ''));

+		// Unique identifier to be linked against item-activities and item-content
+		$item['uri-hash']      = defaults($item, 'uri-hash', self::itemHash($item['uri'], $item['created']));
+
 		// When there is no content then we don't post it
 		if ($item['body'].$item['title'] == '') {
 			logger('No body, no title.');
@ -1288,10 +1356,6 @@ class Item extends BaseObject
 			$item['edited'] = DateTimeFormat::utcNow();
 		}

-		if (($item['author-link'] == "") && ($item['owner-link'] == "")) {
-			logger("Both author-link and owner-link are empty. Called by: " . System::callstack(), LOGGER_DEBUG);
-		}
-
 		$item['plink'] = defaults($item, 'plink', System::baseUrl() . '/display/' . urlencode($item['guid']));

 		// The contact-id should be set before "self::insert" was called - but there seems to be issues sometimes
@ -1718,9 +1782,7 @@ class Item extends BaseObject
 		}

 		$fields = ['uri' => $item['uri'], 'activity' => $activity_index,
-			'uri-hash' => hash('sha1', $item['uri']) . hash('ripemd160', $item['uri'])];
-
-		$saved_item = $item;
+			'uri-hash' => $item['uri-hash']];

 		// We just remove everything that is content
 		foreach (array_merge(self::CONTENT_FIELDLIST, self::MIXED_CONTENT_FIELDLIST) as $field) {
@ -1734,7 +1796,7 @@ class Item extends BaseObject
 		}

 		// Do we already have this content?
-		$item_activity = dba::selectFirst('item-activity', ['id'], ['uri' => $item['uri']]);
+		$item_activity = dba::selectFirst('item-activity', ['id'], ['uri-hash' => $item['uri-hash']]);
 		if (DBM::is_result($item_activity)) {
 			$item['iaid'] = $item_activity['id'];
 			logger('Fetched activity for URI ' . $item['uri'] . ' (' . $item['iaid'] . ')');
@ -1742,9 +1804,8 @@ class Item extends BaseObject
 			$item['iaid'] = dba::lastInsertId();
 			logger('Inserted activity for URI ' . $item['uri'] . ' (' . $item['iaid'] . ')');
 		} else {
-			// This shouldn't happen. But if it does, we simply store it in the item-content table
+			// This shouldn't happen.
 			logger('Could not insert activity for URI ' . $item['uri'] . ' - should not happen');
-			$item = $saved_item;
 			return false;
 		}
 		if ($locked) {
@ -1760,8 +1821,7 @@ class Item extends BaseObject
 	 */
 	private static function insertContent(&$item)
 	{
-		$fields = ['uri' => $item['uri'], 'plink' => $item['plink'],
-			'uri-plink-hash' => hash('sha1', $item['plink']).hash('sha1', $item['uri'])];
+		$fields = ['uri' => $item['uri'], 'uri-plink-hash' => $item['uri-hash']];

 		foreach (array_merge(self::CONTENT_FIELDLIST, self::MIXED_CONTENT_FIELDLIST) as $field) {
 			if (isset($item[$field])) {
@ -1777,7 +1837,7 @@ class Item extends BaseObject
 		}

 		// Do we already have this content?
-		$item_content = dba::selectFirst('item-content', ['id'], ['uri' => $item['uri']]);
+		$item_content = dba::selectFirst('item-content', ['id'], ['uri-plink-hash' => $item['uri-hash']]);
 		if (DBM::is_result($item_content)) {
 			$item['icid'] = $item_content['id'];
 			logger('Fetched content for URI ' . $item['uri'] . ' (' . $item['icid'] . ')');
@ -1785,32 +1845,14 @@ class Item extends BaseObject
 			$item['icid'] = dba::lastInsertId();
 			logger('Inserted content for URI ' . $item['uri'] . ' (' . $item['icid'] . ')');
 		} else {
-			// By setting the ICID value through the worker we should avoid timing problems.
-			// When the locking works, this shouldn't be needed. But better be prepared.
-			Worker::add(PRIORITY_HIGH, 'SetItemContentID', $item['uri']);
-			logger('Could not insert content for URI ' . $item['uri'] . ' - trying asynchronously');
+			// This shouldn't happen.
+			logger('Could not insert content for URI ' . $item['uri'] . ' - should not happen');
 		}
 		if ($locked) {
 			Lock::release('item_insert_content');
 		}
 	}

-	/**
-	 * @brief Set the item content id for a given URI
-	 *
-	 * @param string $uri The item URI
-	 */
-	public static function setICIDforURI($uri)
-	{
-		$item_content = dba::selectFirst('item-content', ['id'], ['uri' => $uri]);
-		if (DBM::is_result($item_content)) {
-			dba::update('item', ['icid' => $item_content['id']], ['icid' => 0, 'uri' => $uri]);
-			logger('Asynchronously set item content id for URI ' . $uri . ' (' . $item_content['id'] . ') - Affected: '. (int)dba::affected_rows());
-		} else {
-			logger('No item-content found for URI ' . $uri);
-		}
-	}
-
 	/**
 	 * @brief Update existing item content entries
 	 *
@ -1828,10 +1870,9 @@ class Item extends BaseObject
 			return false;
 		}

-		$fields = ['activity' => $activity_index,
-			'uri-hash' => hash('sha1', $condition['uri']) . hash('ripemd160', $condition['uri'])];
+		$fields = ['activity' => $activity_index];

-		logger('Update activity for URI ' . $condition['uri']);
+		logger('Update activity for ' . json_encode($condition));

 		dba::update('item-activity', $fields, $condition, true);

@ -1860,14 +1901,7 @@ class Item extends BaseObject
 			$fields = $condition;
 		}

-		if (!empty($item['plink'])) {
-			$fields['uri-plink-hash'] = hash('sha1', $item['plink']) . hash('sha1', $condition['uri']);
-		} else {
-			// Ensure that we don't delete the plink
-			unset($fields['plink']);
-		}
-
-		logger('Update content for URI ' . $condition['uri']);
+		logger('Update content for ' . json_encode($condition));

 		dba::update('item-content', $fields, $condition, true);
 	}
--- a/src/Model/ItemContent.php
+++ b/src/Model/ItemContent.php
@ -93,7 +93,7 @@ class ItemContent extends BaseObject
 			}
 		}

-		$html = Text\BBCode::convert($post['text'] . $post['after'], false, $htmlmode);
+		$html = Text\BBCode::convert($post['text'] . defaults($post, 'after', ''), false, $htmlmode);
 		$msg = Text\HTML::toPlaintext($html, 0, true);
 		$msg = trim(html_entity_decode($msg, ENT_QUOTES, 'UTF-8'));

@ -102,7 +102,7 @@ class ItemContent extends BaseObject
 			if ($post['type'] == 'link') {
 				$link = $post['url'];
 			} elseif ($post['type'] == 'text') {
-				$link = $post['url'];
+				$link = defaults($post, 'url', '');
 			} elseif ($post['type'] == 'video') {
 				$link = $post['url'];
 			} elseif ($post['type'] == 'photo') {
--- a/src/Network/Probe.php
+++ b/src/Network/Probe.php
@ -335,7 +335,7 @@ class Probe
 		}

 		if (x($data, "photo")) {
-			$data["baseurl"] = Network::getUrlMatch(normalise_link($data["baseurl"]), normalise_link($data["photo"]));
+			$data["baseurl"] = Network::getUrlMatch(normalise_link(defaults($data, "baseurl", "")), normalise_link($data["photo"]));
 		} else {
 			$data["photo"] = System::baseUrl().'/images/person-175.jpg';
 		}
@ -1142,7 +1142,7 @@ class Probe
 			}

 			// Older Friendica versions had used the "uid" field differently than newer versions
-			if ($data["nick"] == $data["guid"]) {
+			if (!empty($data["nick"]) && !empty($data["guid"]) && ($data["nick"] == $data["guid"])) {
 				unset($data["guid"]);
 			}
 		}
@ -1390,16 +1390,16 @@ class Probe
 			}
 		}

-		$data["location"] = $xpath->query("//p[contains(@class, 'p-locality')]")->item(0)->nodeValue;
+		$data["location"] = XML::getFirstNodeValue($xpath, "//p[contains(@class, 'p-locality')]");

 		if ($data["location"] == '') {
-			$data["location"] = $xpath->query("//p[contains(@class, 'location')]")->item(0)->nodeValue;
+			$data["location"] = XML::getFirstNodeValue($xpath, "//p[contains(@class, 'location')]");
 		}

-		$data["about"] = $xpath->query("//p[contains(@class, 'p-note')]")->item(0)->nodeValue;
+		$data["about"] = XML::getFirstNodeValue($xpath, "//p[contains(@class, 'p-note')]");

 		if ($data["about"] == '') {
-			$data["about"] = $xpath->query("//p[contains(@class, 'summary')]")->item(0)->nodeValue;
+			$data["about"] = XML::getFirstNodeValue($xpath, "//p[contains(@class, 'summary')]");
 		}

 		$avatar = $xpath->query("//img[contains(@class, 'u-photo')]")->item(0);
--- a/src/Protocol/Diaspora.php
+++ b/src/Protocol/Diaspora.php
@ -2005,6 +2005,9 @@ class Diaspora

 		$datarray["body"] = $verb;

+		// Diaspora doesn't provide a date for likes
+		$datarray["changed"] = $datarray["created"] = $datarray["edited"] = DateTimeFormat::utcNow();
+
 		// like on comments have the comment as parent. So we need to fetch the toplevel parent
 		if ($parent_item["id"] != $parent_item["parent"]) {
 			$toplevel = Item::selectFirst(['origin'], ['id' => $parent_item["parent"]]);
--- a/src/Protocol/PortableContact.php
+++ b/src/Protocol/PortableContact.php
@ -19,6 +19,7 @@ use Friendica\Network\Probe;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
 use Friendica\Protocol\Diaspora;
+use Friendica\Util\XML;
 use dba;
 use DOMDocument;
 use DOMXPath;
@ -916,7 +917,7 @@ class PortableContact
 			return false;
 		}

-		$server["site_name"] = $xpath->evaluate("//head/title/text()")->item(0)->nodeValue;
+		$server["site_name"] = XML::getFirstNodeValue($xpath, '//head/title/text()');
 		return $server;
 	}

@ -1003,7 +1004,7 @@ class PortableContact
 		// Quit if there is a timeout.
 		// But we want to make sure to only quit if we are mostly sure that this server url fits.
 		if (DBM::is_result($gserver) && ($orig_server_url == $server_url) &&
-			($serverret['errno'] == CURLE_OPERATION_TIMEDOUT)) {
+			(!$serverret["success"] && ($serverret['errno'] == CURLE_OPERATION_TIMEDOUT))) {
 			logger("Connection to server ".$server_url." timed out.", LOGGER_DEBUG);
 			dba::update('gserver', ['last_failure' => DateTimeFormat::utcNow()], ['nurl' => normalise_link($server_url)]);
 			return false;
@ -1018,7 +1019,7 @@ class PortableContact
 			$serverret = Network::curl($server_url."/.well-known/host-meta", false, $redirects, ['timeout' => 20]);

 			// Quit if there is a timeout
-			if ($serverret['errno'] == CURLE_OPERATION_TIMEDOUT) {
+			if (!$serverret["success"] && ($serverret['errno'] == CURLE_OPERATION_TIMEDOUT)) {
 				logger("Connection to server ".$server_url." timed out.", LOGGER_DEBUG);
 				dba::update('gserver', ['last_failure' => DateTimeFormat::utcNow()], ['nurl' => normalise_link($server_url)]);
 				return false;
@ -1230,8 +1231,14 @@ class PortableContact
 						$site_name = $data->site->name;

 						$data->site->closed = self::toBoolean($data->site->closed);
+
+						if (!empty($data->site->private)) {
 							$data->site->private = self::toBoolean($data->site->private);
+						}
+
+						if (!empty($data->site->inviteonly)) {
 							$data->site->inviteonly = self::toBoolean($data->site->inviteonly);
+						}

 						if (!$data->site->closed && !$data->site->private and $data->site->inviteonly) {
 							$register_policy = REGISTER_APPROVE;
@ -1325,7 +1332,9 @@ class PortableContact
 						$noscrape = $data->no_scrape_url;
 					}
 					$version = $data->version;
+					if (!empty($data->site_name)) {
 						$site_name = $data->site_name;
+					}
 					$info = $data->info;
 					$register_policy = constant($data->register_policy);
 					$platform = $data->platform;
@ -1714,7 +1723,9 @@ class PortableContact
 			$contact_type = -1;
 			$generation = $default_generation;

+			if (!empty($entry->displayName)) {
 				$name = $entry->displayName;
+			}

 			if (isset($entry->urls)) {
 				foreach ($entry->urls as $url) {
--- a/src/Worker/CronJobs.php
+++ b/src/Worker/CronJobs.php
@ -36,7 +36,8 @@ class CronJobs
 		// Call possible post update functions
 		// see src/Database/PostUpdate.php for more details
 		if ($command == 'post_update') {
-			PostUpdate::update();
+// Post updates will be reenabled (hopefully in a few days) when most item works are done
+//			PostUpdate::update();
 			return;
 		}

--- a/src/Worker/Delivery.php
+++ b/src/Worker/Delivery.php
@ -44,6 +44,7 @@ class Delivery extends BaseObject
 				return;
 			}
 			$uid = $target_item['uid'];
+			$items = [];
 		} elseif ($cmd == self::SUGGESTION) {
 			$target_item = dba::selectFirst('fsuggest', [], ['id' => $item_id]);
 			if (!DBM::is_result($target_item)) {
@ -127,6 +128,10 @@ class Delivery extends BaseObject
 			}
 		}

+		if (empty($items)) {
+			logger('No delivery data for  ' . $cmd . ' - Item ID: ' .$item_id . ' - Contact ID: ' . $contact_id);
+		}
+
 		$owner = User::getOwnerDataById($uid);
 		if (!DBM::is_result($owner)) {
 			return;
@ -271,7 +276,7 @@ class Delivery extends BaseObject

 		// We don't have a relationship with contacts on a public post.
 		// Se we transmit with the new method and via Diaspora as a fallback
-		if (($items[0]['uid'] == 0) || ($contact['uid'] == 0)) {
+		if (!empty($items) && (($items[0]['uid'] == 0) || ($contact['uid'] == 0))) {
 			// Transmit in public if it's a relay post
 			$public_dfrn = ($contact['contact-type'] == ACCOUNT_TYPE_RELAY);

--- a/src/Worker/Expire.php
+++ b/src/Worker/Expire.php
@ -42,12 +42,12 @@ class Expire {
 			// Normally we shouldn't have orphaned data at all.
 			// If we do have some, then we have to check why.
 			logger('Deleting orphaned item activities - start', LOGGER_DEBUG);
-			$condition = ["NOT EXISTS (SELECT `iaid` FROM `item` WHERE `item`.`uri` = `item-activity`.`uri`)"];
+			$condition = ["NOT EXISTS (SELECT `iaid` FROM `item` WHERE `item`.`iaid` = `item-activity`.`id`)"];
 			dba::delete('item-activity', $condition);
 			logger('Orphaned item activities deleted: ' . dba::affected_rows(), LOGGER_DEBUG);

 			logger('Deleting orphaned item content - start', LOGGER_DEBUG);
-			$condition = ["NOT EXISTS (SELECT `icid` FROM `item` WHERE `item`.`uri` = `item-content`.`uri`)"];
+			$condition = ["NOT EXISTS (SELECT `icid` FROM `item` WHERE `item`.`icid` = `item-content`.`id`)"];
 			dba::delete('item-content', $condition);
 			logger('Orphaned item content deleted: ' . dba::affected_rows(), LOGGER_DEBUG);

--- a/src/Worker/Notifier.php
+++ b/src/Worker/Notifier.php
@ -378,7 +378,7 @@ class Notifier {
 		}

 		// If this is a public message and pubmail is set on the parent, include all your email contacts
-		if (function_exists('imap_open') && !Config::get('system','imap_disabled')) {
+		if (!empty($target_item) && function_exists('imap_open') && !Config::get('system','imap_disabled')) {
 			if (!strlen($target_item['allow_cid']) && !strlen($target_item['allow_gid'])
 				&& !strlen($target_item['deny_cid']) && !strlen($target_item['deny_gid'])
 				&& intval($target_item['pubmail'])) {
@ -412,7 +412,7 @@ class Notifier {
 		// delivery loop
 		if (DBM::is_result($r)) {
 			foreach ($r as $contact) {
-				logger("Deliver ".$target_item["guid"]." to ".$contact['url']." via network ".$contact['network'], LOGGER_DEBUG);
+				logger("Deliver ".$item_id." to ".$contact['url']." via network ".$contact['network'], LOGGER_DEBUG);

 				Worker::add(['priority' => $a->queue['priority'], 'created' => $a->queue['created'], 'dont_fork' => true],
 						'Delivery', $cmd, $item_id, (int)$contact['id']);
--- a/src/Worker/SetItemContentID.php
+++ b/src/Worker/SetItemContentID.php
@ -1,21 +0,0 @@
-<?php
-/**
- * @file src/Worker/SetItemContentID.php
- * @brief This script sets the "icid" value in the item table if it couldn't set before.
- *
- * This script is started from mod/item.php to fix timing problems.
- */
-
-namespace Friendica\Worker;
-
-use Friendica\Model\Item;
-
-class SetItemContentID {
-	public static function execute($uri = '') {
-		if (empty($uri)) {
-			return;
-		}
-
-		Item::setICIDforURI($uri);
-	}
-}