From 5cd2ece3ba07ea132f1bda9ec4ab76828cc77f51 Mon Sep 17 00:00:00 2001
From: Zac Medico <zmedico@gentoo.org>
Date: Mon, 2 Nov 2009 01:45:57 +0000
Subject: [PATCH] Don't call FakeVartree.sync() redundantly when backtracking.

svn path=/main/trunk/; revision=14774
---
 pym/_emerge/PackageVirtualDbapi.py | 7 +++++++
 pym/_emerge/depgraph.py            | 5 ++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/pym/_emerge/PackageVirtualDbapi.py b/pym/_emerge/PackageVirtualDbapi.py
index adf269116..e557f0489 100644
--- a/pym/_emerge/PackageVirtualDbapi.py
+++ b/pym/_emerge/PackageVirtualDbapi.py
@@ -2,6 +2,7 @@
 # Distributed under the terms of the GNU General Public License v2
 # $Id$
 
+import sys
 import portage
 
 class PackageVirtualDbapi(portage.dbapi):
@@ -37,6 +38,12 @@ class PackageVirtualDbapi(portage.dbapi):
 		obj._cpv_map = self._cpv_map.copy()
 		return obj
 
+	def __bool__(self):
+		return bool(self._cpv_map)
+
+	if sys.hexversion < 0x3000000:
+		__nonzero__ = __bool__
+
 	def __iter__(self):
 		return iter(self._cpv_map.values())
 
diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index 72c147ee2..5c66cf581 100644
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -270,7 +270,10 @@ class depgraph(object):
 				"--buildpkgonly" not in self._frozen_config.myopts
 
 			fake_vartree = self._frozen_config.trees[myroot]["vartree"]
-			fake_vartree.sync()
+			if not fake_vartree.dbapi:
+				# This needs to be called for the first depgraph, but not for
+				# backtracking depgraphs that share the same frozen_config.
+				fake_vartree.sync()
 
 			if preload_installed_pkgs:
 				vardb = fake_vartree.dbapi
-- 
2.26.2