Prevent a potential KeyError when removing world from the digraph for --prune display. (trunk r7344)

svn path=/main/branches/2.1.2/; revision=7347

1 files changed, 2 insertions, 1 deletions

diff --git a/bin/emerge b/bin/emerge
index f3952ea5..84cd16a5 100755
--- a/bin/emerge
+++ b/bin/emerge
@@ -5504,7 +5504,8 @@ def action_depclean(settings, trees, ldpath_mtimes,
 	elif action == "prune":
 		# Prune really uses all installed instead of world.  It's not a real
 		# reverse dependency so don't display it as such.
-		graph.remove("world")
+		if graph.contains("world"):
+			graph.remove("world")
 		for atom in args_set:
 			for pkg in vardb.match(atom):
 				if not fakedb.cpv_exists(pkg):