Fix further notes and warnings

src/Model/GServer.php

@@ -1061,12 +1061,12 @@ class GServer
 			$attr = [];
 			if ($node->attributes->length) {
 				foreach ($node->attributes as $attribute) {
-					$attribute->value = @trim($attribute->value);
-					if (empty($attribute->value)) {
+					$value = trim($attribute->value);
+					if (empty($value)) {
 						continue;
 					}
 
-					$attr[$attribute->name] = $attribute->value;
+					$attr[$attribute->name] = $value;
 				}
 
 				if (empty($attr['name']) || empty($attr['content'])) {
@@ -1117,12 +1117,12 @@ class GServer
 			$attr = [];
 			if ($node->attributes->length) {
 				foreach ($node->attributes as $attribute) {
-					$attribute->value = @trim($attribute->value);
-					if (empty($attribute->value)) {
+					$value = trim($attribute->value);
+					if (empty($value)) {
 						continue;
 					}
 
-					$attr[$attribute->name] = $attribute->value;
+					$attr[$attribute->name] = $value;
 				}
 
 				if (empty($attr['property']) || empty($attr['content'])) {

src/Protocol/ActivityPub/Transmitter.php

@@ -653,6 +653,9 @@ class Transmitter
 	public static function ItemArrayFromMail($mail_id)
 	{
 		$mail = DBA::selectFirst('mail', [], ['id' => $mail_id]);
+		if (!DBA::isResult($mail)) {
+			return [];
+		}
 
 		$reply = DBA::selectFirst('mail', ['uri'], ['parent-uri' => $mail['parent-uri'], 'reply' => false]);
 
@@ -1234,6 +1237,10 @@ class Transmitter
 	 */
 	public static function createNote($item)
 	{
+		if (empty($item)) {
+			return [];
+		}
+
 		if ($item['event-type'] == 'event') {
 			$type = 'Event';
 		} elseif (!empty($item['title'])) {