Add changelog

Author: matticbot

.github/changelog/2532-from-description

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fixed
+
+False mention email notifications for users in CC field without actual mention tags.

tests/phpunit/tests/includes/class-test-mailer.php

@@ -832,6 +832,13 @@ public function test_mention_with_array() {
 			'object' => array(
 				'id'      => 'https://example.com/post/1',
 				'content' => 'Test mention',
+				'tag'     => array(
+					array(
+						'type' => 'Mention',
+						'href' => Actors::get_by_id( $user_id )->get_id(),
+						'name' => '@test',
+					),
+				),
 			),
 			'cc'     => array( Actors::get_by_id( $user_id )->get_id() ),
 		);
@@ -954,6 +961,13 @@ public function test_mention_filters_recipients() {
 			'object' => array(
 				'id'      => 'https://example.com/post/1',
 				'content' => 'Test mention',
+				'tag'     => array(
+					array(
+						'type' => 'Mention',
+						'href' => Actors::get_by_id( $user_id )->get_id(),
+						'name' => '@test',
+					),
+				),
 			),
 			// Only user_id is in CC, not other_user_id.
 			'cc'     => array( Actors::get_by_id( $user_id )->get_id() ),