@@ -, +, @@ 
---
 pym/portage/dbapi/vartree.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/pym/portage/dbapi/vartree.py	
+++ a/pym/portage/dbapi/vartree.py	
@@ -1178,8 +1178,8 @@ class vardbapi(dbapi):
 			call.
 			"""
 
-			if not isinstance(path_iter, list):
-				path_iter = list(path_iter)
+			# ensure not to modify the argument
+			path_iter = list(path_iter)
 			owners_cache = self._populate()
 			vardb = self._vardb
 			root = vardb._eroot
--