diff --git a/mod/contacts.php b/mod/contacts.php
index ae23974e03..f4cbbf44de 100644
--- a/mod/contacts.php
+++ b/mod/contacts.php
@@ -188,7 +188,7 @@ function contacts_post(App $a)
 
 	Addon::callHooks('contact_edit_post', $_POST);
 
-	$profile_id = intval($_POST['profile-assign']);
+	$profile_id = intval(defaults($_POST, 'profile-assign', 0));
 	if ($profile_id) {
 		if (!DBA::exists('profile', ['id' => $profile_id, 'uid' => local_user()])) {
 			notice(L10n::t('Could not locate selected profile.') . EOL);
@@ -200,11 +200,11 @@ function contacts_post(App $a)
 
 	$notify = intval($_POST['notify']);
 
-	$fetch_further_information = intval($_POST['fetch_further_information']);
+	$fetch_further_information = intval(defaults($_POST, 'fetch_further_information', 0));
 
-	$ffi_keyword_blacklist = escape_tags(trim($_POST['ffi_keyword_blacklist']));
+	$ffi_keyword_blacklist = escape_tags(trim(defaults($_POST, 'ffi_keyword_blacklist', '')));
 
-	$priority = intval($_POST['poll']);
+	$priority = intval(defaults($_POST, 'poll', 0));
 	if ($priority > 5 || $priority < 0) {
 		$priority = 0;
 	}
diff --git a/mod/dfrn_notify.php b/mod/dfrn_notify.php
index ee6290d663..26985527be 100644
--- a/mod/dfrn_notify.php
+++ b/mod/dfrn_notify.php
@@ -213,6 +213,14 @@ function dfrn_dispatch_public($postdata)
 
 	// We now have some contact, so we fetch it
 	$importer = DBA::fetchFirst("SELECT *, `name` as `senderName`
+					'' AS `uprvkey`,
+					'UTC' AS `timezone`,
+					'' AS `nickname`,
+					'' AS `sprvkey`,
+					'' AS `spubkey`,
+					0 AS `page-flags`,
+					0 AS `account-type`,
+					0 AS `prvnets`
 					FROM `contact`
 					WHERE NOT `blocked` AND `id` = ? LIMIT 1",
 					$contact['id']);
diff --git a/mod/dirfind.php b/mod/dirfind.php
index 40275523fd..0171da1b04 100644
--- a/mod/dirfind.php
+++ b/mod/dirfind.php
@@ -211,7 +211,7 @@ function dirfind_content(App $a, $prefix = "") {
 						$photo_menu = [];
 					}
 				} else {
-					$connlnk = System::baseUrl().'/follow/?url='.(($jj->connect) ? $jj->connect : $jj->url);
+					$connlnk = System::baseUrl().'/follow/?url='.(!empty($jj->connect) ? $jj->connect : $jj->url);
 					$conntxt = L10n::t('Connect');
 					$photo_menu = [
 						'profile' => [L10n::t("View Profile"), Contact::magicLink($jj->url)],
diff --git a/mod/photos.php b/mod/photos.php
index b7e678487a..04d4138fc6 100644
--- a/mod/photos.php
+++ b/mod/photos.php
@@ -123,7 +123,10 @@ function photos_init(App $a) {
 		}
 
 		$a->page['aside'] .= $vcard_widget;
-		$a->page['aside'] .= $photo_albums_widget;
+
+		if (!empty($photo_albums_widget)) {
+			$a->page['aside'] .= $photo_albums_widget;
+		}
 
 		$tpl = get_markup_template("photos_head.tpl");
 
diff --git a/src/App.php b/src/App.php
index 02215d2e69..f583f151a6 100644
--- a/src/App.php
+++ b/src/App.php
@@ -1307,11 +1307,11 @@ class App
 		// Only arrays are serialized in database, so we have to unserialize sparingly
 		$value = is_string($v) && preg_match("|^a:[0-9]+:{.*}$|s", $v) ? unserialize($v) : $v;
 
-		if (!isset($this->config[$uid])) {
+		if (!isset($this->config[$uid]) || !is_array($this->config[$uid])) {
 			$this->config[$uid] = [];
 		}
 
-		if (!isset($this->config[$uid][$cat])) {
+		if (!isset($this->config[$uid][$cat]) || !is_array($this->config[$uid][$cat])) {
 			$this->config[$uid][$cat] = [];
 		}
 
diff --git a/src/Content/Text/BBCode.php b/src/Content/Text/BBCode.php
index 6c21a37cba..da9279900e 100644
--- a/src/Content/Text/BBCode.php
+++ b/src/Content/Text/BBCode.php
@@ -585,7 +585,7 @@ class BBCode extends BaseObject
 					$return .= sprintf('<h4><a href="%s">%s</a></h4>', $data['url'], $data['title']);
 				}
 
-				if ($data["description"] != "" && $data["description"] != $data["title"]) {
+				if (!empty($data["description"]) && $data["description"] != $data["title"]) {
 					// Sanitize the HTML by converting it to BBCode
 					$bbcode = HTML::toBBCode($data["description"]);
 					$return .= sprintf('<blockquote>%s</blockquote>', trim(self::convert($bbcode)));
@@ -627,15 +627,15 @@ class BBCode extends BaseObject
 		}
 
 		// If the link already is included in the post, don't add it again
-		if (($data["url"] != "") && strpos($data["text"], $data["url"])) {
+		if (!empty($data["url"]) && strpos($data["text"], $data["url"])) {
 			return $data["text"] . $data["after"];
 		}
 
 		$text = $data["text"];
 
-		if (($data["url"] != "") && ($data["title"] != "")) {
+		if (!empty($data["url"]) && ($data["title"] != "")) {
 			$text .= "\n[url=" . $data["url"] . "]" . $data["title"] . "[/url]";
-		} elseif (($data["url"] != "")) {
+		} elseif (!empty($data["url"])) {
 			$text .= "\n[url]" . $data["url"] . "[/url]";
 		}
 
diff --git a/src/Content/Text/Markdown.php b/src/Content/Text/Markdown.php
index ac598d0fc4..71d1a7b849 100644
--- a/src/Content/Text/Markdown.php
+++ b/src/Content/Text/Markdown.php
@@ -53,6 +53,10 @@ class Markdown extends BaseObject
 
 		$data = Contact::getDetailsByAddr($match[2]);
 
+		if (empty($data)) {
+			return;
+		}
+
 		$name = $match[1];
 
 		if ($name == '') {
diff --git a/src/Core/Addon.php b/src/Core/Addon.php
index bfb2a1e8fd..e4acd6e9d3 100644
--- a/src/Core/Addon.php
+++ b/src/Core/Addon.php
@@ -311,7 +311,12 @@ class Addon
 			foreach ($ll as $l) {
 				$l = trim($l, "\t\n\r */");
 				if ($l != "") {
-					list($type, $v) = array_map("trim", explode(":", $l, 2));
+					$addon_info = array_map("trim", explode(":", $l, 2));
+					if (count($addon_info) < 2) {
+						continue;
+					}
+
+					list($type, $v) = $addon_info;
 					$type = strtolower($type);
 					if ($type == "author" || $type == "maintainer") {
 						$r = preg_match("|([^<]+)<([^>]+)>|", $v, $m);
diff --git a/src/Model/Event.php b/src/Model/Event.php
index 16d1ada27a..8e67da6352 100644
--- a/src/Model/Event.php
+++ b/src/Model/Event.php
@@ -76,12 +76,14 @@ class Event extends BaseObject
 
 		if (!$event['nofinish']) {
 			$o .= '<div class="event-end" ><span class="event-label">' . L10n::t('Finishes:') . '</span>&nbsp;<span class="dtend" title="'
-				. DateTimeFormat::utc($event['finish'], (($event['adjust']) ? DateTimeFormat::ATOM : 'Y-m-d\TH:i:s'))
+				. DateTimeFormat::utc($event['finish'], (!empty($event['adjust']) ? DateTimeFormat::ATOM : 'Y-m-d\TH:i:s'))
 				. '" >' . $event_end
 				. '</span></div>' . "\r\n";
 		}
 
-		$o .= '<div class="description event-description">' . BBCode::convert($event['desc'], false, $simple) . '</div>' . "\r\n";
+		if (!empty($event['desc'])) {
+			$o .= '<div class="description event-description">' . BBCode::convert($event['desc'], false, $simple) . '</div>' . "\r\n";
+		}
 
 		if (strlen($event['location'])) {
 			$o .= '<div class="event-location"><span class="event-label">' . L10n::t('Location:') . '</span>&nbsp;<span class="location">'
diff --git a/src/Protocol/OStatus.php b/src/Protocol/OStatus.php
index dca47e31b9..bf0abc643d 100644
--- a/src/Protocol/OStatus.php
+++ b/src/Protocol/OStatus.php
@@ -1610,6 +1610,8 @@ class OStatus
 			$contact["alias"] = $contact["url"];
 		}
 
+		$contact['account-type'] = $owner['account-type'];
+
 		return $contact;
 	}
 
@@ -1640,7 +1642,6 @@ class OStatus
 		}
 
 		$contact = self::contactEntry($repeated_item['author-link'], $owner);
-		$contact['account-type'] = $contact['contact-type'];
 
 		$title = $owner["nick"]." repeated a notice by ".$contact["nick"];