diff --git a/addressbook/inc/class.addressbook_groupdav.inc.php b/addressbook/inc/class.addressbook_groupdav.inc.php
index a0b0f5216d..6c2148178e 100644
--- a/addressbook/inc/class.addressbook_groupdav.inc.php
+++ b/addressbook/inc/class.addressbook_groupdav.inc.php
@@ -263,7 +263,7 @@ class addressbook_groupdav extends Api\CalDAV\Handler
 			}
 		}
 		// last chunk or no chunking: add accounts from different repo and report missing multiget urls
-		if (!$start || count($contacts) < $start[1])
+		if (!$start || (empty($contact)?0:count($contacts)) < $start[1])
 		{
 			//error_log(__METHOD__."('$path', ".array2string($filter).", ".array2string($start)."; $report_not_found_multiget_ids) last chunk detected: count()=".count($contacts)." < $start[1]");
 			// add accounts after contacts, if enabled and stored in different repository
diff --git a/api/src/Db.php b/api/src/Db.php
index 9c0c6caf6e..48e542d6e8 100644
--- a/api/src/Db.php
+++ b/api/src/Db.php
@@ -1939,7 +1939,7 @@ class Db
 		{
 			$table = self::$tablealiases[$table];
 		}
-		if (count($data))
+		if (!empty($data))
 		{
 			$inputarr = false;
 			if ($use_prepared_statement && $this->Link_ID->_bindInputArray)	// eg. MaxDB
diff --git a/api/src/Hooks.php b/api/src/Hooks.php
index 83085c6ed2..67f825f1bb 100644
--- a/api/src/Hooks.php
+++ b/api/src/Hooks.php
@@ -194,7 +194,8 @@ class Hooks
 		if (!isset(self::$locations)) self::read();
 
 		//error_log(__METHOD__.__LINE__.array2string(self::$locations[$location]));
-		return $return_methods ? self::$locations[$location][$app] : count(self::$locations[$location][$app]);
+		return $return_methods ? self::$locations[$location][$app] :
+			(empty(self::$locations[$location][$app]) ? 0 : count(self::$locations[$location][$app]));
 	}
 
 	/**
diff --git a/api/src/Link.php b/api/src/Link.php
index 5eba4b6f62..c191762b7e 100644
--- a/api/src/Link.php
+++ b/api/src/Link.php
@@ -313,13 +313,13 @@ class Link extends Link\Storage
 		{
 			//error_log(__METHOD__.'() items in title-cache: '.count(self::$title_cache).' file-access-cache: '.count(self::$file_access_cache));
 
-			if (count(self::$title_cache > self::TITLE_CACHE_SIZE))
+			if (count(self::$title_cache) > self::TITLE_CACHE_SIZE)
 			{
 				self::$title_cache = array_slice(self::$title_cache, -self::TITLE_CACHE_SIZE);
 			}
 			Cache::setSession(__CLASS__, 'link_title_cache', self::$title_cache);
 
-			if (count(self::$file_access_cache > self::FILE_ACCESS_CACHE_SIZE))
+			if (count(self::$file_access_cache) > self::FILE_ACCESS_CACHE_SIZE)
 			{
 				self::$file_access_cache = array_slice(self::$file_access_cache, -self::FILE_ACCESS_CACHE_SIZE);
 			}
diff --git a/mail/inc/class.mail_ui.inc.php b/mail/inc/class.mail_ui.inc.php
index f74fb31b36..e0f3c50ad8 100644
--- a/mail/inc/class.mail_ui.inc.php
+++ b/mail/inc/class.mail_ui.inc.php
@@ -1935,46 +1935,45 @@ $filter['before']= date("d-M-Y", $cutoffdate2);
 			//error_log(__METHOD__.__LINE__.array2string($header));
 			if (in_array("attachments", $cols))
 			{
-				if($header['mimetype'] == 'multipart/mixed' ||
-					$header['mimetype'] == 'multipart/signed' ||
-					$header['mimetype'] == 'multipart/related' ||
-					$header['mimetype'] == 'multipart/report' ||
-					$header['mimetype'] == 'text/calendar' ||
-					$header['mimetype'] == 'text/html' ||
+				if (!empty($header['attachments']) && (in_array($header['mimetype'], array(
+						'multipart/mixed', 'multipart/signed', 'multipart/related', 'multipart/report',
+						'text/calendar', 'text/html', 'multipart/alternative',
+					)) ||
 					substr($header['mimetype'],0,11) == 'application' ||
 					substr($header['mimetype'],0,5) == 'audio' ||
-					substr($header['mimetype'],0,5) == 'video' ||
-					$header['mimetype'] == 'multipart/alternative')
+					substr($header['mimetype'],0,5) == 'video'))
 				{
 					$image = Api\Html::image('mail','attach');
-					$imageHTMLBlock = '';
 					$datarowid = $this->createRowID($_folderName,$message_uid,true);
 					$attachments = $header['attachments'];
-					if (count($attachments)<1)
+					if (count($attachments) == 1)
 					{
-						$image = '&nbsp;';
-					}
-					if (count($attachments)==1)
-					{
-						$imageHTMLBlock = self::createAttachmentBlock($attachments, $datarowid, $header['uid'],$_folderName);
 						$image = Api\Html::image('mail','attach',$attachments[0]['name'].(!empty($attachments[0]['mimeType'])?' ('.$attachments[0]['mimeType'].')':''));
 					}
-					if (count($attachments)>1)
+					else
 					{
-						$imageHTMLBlock = self::createAttachmentBlock($attachments, $datarowid, $header['uid'],$_folderName);
 						$image = Api\Html::image('mail','attach',lang('%1 attachments',count($attachments)));
 					}
+					$imageHTMLBlock = self::createAttachmentBlock($attachments, $datarowid, $header['uid'],$_folderName);
 
 					$attachmentFlag = $image;
-				} else {
-					$attachmentFlag ='&nbsp;';
+				}
+				else
+				{
+					$attachmentFlag = '&nbsp;';
+					$imageHTMLBlock = '';
 				}
 				// show priority flag
-				if ($header['priority'] < 3) {
+				if ($header['priority'] < 3)
+				{
 					 $image = Api\Html::image('mail','prio_high');
-				} elseif ($header['priority'] > 3) {
+				}
+				elseif ($header['priority'] > 3)
+				{
 					$image = Api\Html::image('mail','prio_low');
-				} else {
+				}
+				else
+				{
 					$image = '';
 				}
 				// show a flag for flagged messages