Allow system virtuals to be pruned from the world file in cases where the matched package is the only provider of that virtual. (trunk r7197)

svn path=/main/branches/2.1.2/; revision=7198

1 files changed, 7 insertions, 3 deletions

diff --git a/bin/emerge b/bin/emerge
index 30541ef6d..f10f56c95 100755
--- a/bin/emerge
+++ b/bin/emerge
@@ -726,12 +726,16 @@ def create_world_atom(pkg_key, metadata, args_set, sets, portdb):
 		# Unlike world atoms, system atoms are not greedy for slots, so they
 		# can't be safely excluded from world if they are slotted.
 		system_atom = sets["system"].findAtomForPackage(pkg_key, metadata)
-		if system_atom and \
-			not portage.dep_getkey(system_atom).startswith("virtual/"):
+		if system_atom:
+			if not portage.dep_getkey(system_atom).startswith("virtual/"):
+				return None
 			# System virtuals aren't safe to exclude from world since they can
 			# match multiple old-style virtuals but only one of them will be
 			# pulled in by update or depclean.
-			return None
+			providers = portdb.mysettings.getvirtuals().get(
+				portage.dep_getkey(system_atom))
+			if providers and len(providers) == 1 and providers[0] == cp:
+				return None
 	return new_world_atom
 
 def filter_iuse_defaults(iuse):