Fixing queries due the single database see #3910

main/document/downloadfolder.inc.php

@@ -66,6 +66,7 @@ if (api_is_allowed_to_edit()) {
 					docs.path 			LIKE '".$querypath."/%' AND 
 					docs.filetype		= 'file' AND props.visibility<>'2' AND 
 					props.to_group_id	= ".$to_group_id." AND 
+					props.c_id          = ".$course_id." AND
 					docs.c_id 			= ".$course_id." ";
 	$query = Database::query($sql);
 	// Add tem to the zip file