expand_new_virt: use stack for recursion

diff --git a/pym/_emerge/actions.py b/pym/_emerge/actions.py
index f2f4181140f075f5185af9150f3fb9d8f58b836d..e4e87da764ec5ca2d8a8cf839cc8ed6c79969b04 100644 (file)
--- a/pym/_emerge/actions.py
+++ b/pym/_emerge/actions.py
@@ -1289,39 +1289,40 @@ def action_deselect(settings, trees, opts, atoms):
                        world_set.unlock()
        return os.EX_OK
 
-def expand_new_virt(vardb, atom, _traversed=None):
+def expand_new_virt(vardb, atom):
        """
        Iterate over the recursively expanded RDEPEND atoms of
        a new-style virtual. If atom is not a new-style virtual
        or it does not match an installed package then it is
        yielded without any expansion.
        """
-       matches = vardb.match(atom)
-       if not (matches and portage.cpv_getkey(matches[-1]).startswith("virtual/")):
-               yield atom
-               return
-
-       virt_cpv = matches[-1]
-       rdepend, use = vardb.aux_get(virt_cpv, ["RDEPEND", "USE"])
-       use = frozenset(use.split())
-       success, atoms = portage.dep_check(rdepend,
-               None, vardb.settings, myuse=use,
-               myroot=vardb.root, trees={vardb.root:{"porttree":vardb.vartree,
-               "vartree":vardb.vartree}})
+       traversed = set()
+       stack = [atom]
+
+       while stack:
+               atom = stack.pop()
+               matches = vardb.match(atom)
+               if not (matches and \
+                       portage.cpv_getkey(matches[-1]).startswith("virtual/")):
+                       yield atom
+                       continue
 
-       if not success:
-               yield atom
-               return
+               virt_cpv = matches[-1]
+               if virt_cpv in traversed:
+                       continue
 
-       if _traversed is None:
-               _traversed = set([atom])
+               traversed.add(virt_cpv)
+               rdepend, use = vardb.aux_get(virt_cpv, ["RDEPEND", "USE"])
+               use = frozenset(use.split())
+               success, atoms = portage.dep_check(rdepend,
+                       None, vardb.settings, myuse=use,
+                       myroot=vardb.root, trees={vardb.root:{"porttree":vardb.vartree,
+                       "vartree":vardb.vartree}})
 
-       for child1 in atoms:
-               if child1 not in _traversed:
-                       _traversed.add(child1)
-                       for child2 in expand_new_virt(vardb, child1,
-                               _traversed=_traversed):
-                               yield child2
+               if success:
+                       stack.extend(atoms)
+               else:
+                       yield atom
 
 class _info_pkgs_ver(object):
        def __init__(self, ver, repo_suffix, provide_suffix):