Ticket #30815: 30815.2.patch

src/wp-admin/includes/class-wp-filesystem-ftpext.php

@@ -275 +275 @@
          */
         public function exists($file) {
                 $list = @ftp_nlist($this->link, $file);
+
+                if ( empty( $list ) && $this->is_dir( $file ) ) {
+                        return true; // File is an empty directory.
+                }
+
                 return !empty($list); //empty list = no file, so invert.
         }
         /**

src/wp-admin/includes/class-wp-filesystem-ftpsockets.php

@@ -274 +274 @@
          */
         public function exists( $file ) {
                 $list = $this->ftp->nlist( $file );
+
+                if ( empty( $list ) && $this->is_dir( $file ) ) {
+                        return true; // File is an empty directory.
+                }
+
                 return !empty( $list ); //empty list = no file, so invert.
                 // Return $this->ftp->is_exists($file); has issues with ABOR+426 responses on the ncFTPd server.
         }