Add upstream plugins

Signed-off-by: Adrian Nöthlich <git@promasu.tech>

wp-content/plugins/all-in-one-event-calendar/lib/post/content.php

@@ -0,0 +1,38 @@
+<?php
+
+/**
+ * Checks if processed page is calendar default page and post has content.
+ *
+ * @author     Time.ly Network Inc.
+ * @since      2.0
+ *
+ * @package    AI1EC
+ * @subpackage AI1EC.Lib
+ */
+class Ai1ec_Post_Content_Check extends Ai1ec_Base {
+
+    /**
+     * Checks if post has content for default calendar page and if not sets one.
+     *
+     * @param WP_Post|null $post Post object.
+     *
+     * @return void Method does not return.
+     */
+    public function check_content( $post ) {
+        if (
+            null === $post ||
+            ! is_object( $post ) ||
+            ! isset( $post->post_content )
+        ) {
+            return;
+        }
+        if (
+            empty( $post->post_content ) &&
+            is_page() &&
+            $post->ID === $this->_registry->get( 'model.settings' )
+                ->get( 'calendar_page_id' )
+        ) {
+            $post->post_content = '<!-- Time.ly Calendar placeholder -->';
+        }
+    }
+}