From 0816e0db36fbc5898278a34bf2249975bc99da30 Mon Sep 17 00:00:00 2001
From: Zac Medico <zmedico@gentoo.org>
Date: Sun, 18 Oct 2009 04:04:45 +0000
Subject: [PATCH] Automatically create a fallback setconfig, so emerge isn't
 crippled due to misssing/corrupt/outdated sets.conf. This is especially
 important since WorldSet has been renamed to WorldSelectedSet, and thus new
 and old sets.conf files are incompatible. (trunk r14630)

svn path=/main/branches/2.1.7/; revision=14658
---
 pym/_emerge/main.py | 51 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/pym/_emerge/main.py b/pym/_emerge/main.py
index 10e605e56..5007ecfef 100644
--- a/pym/_emerge/main.py
+++ b/pym/_emerge/main.py
@@ -778,6 +778,55 @@ def ionice(settings):
 		out.eerror("PORTAGE_IONICE_COMMAND returned %d" % (rval,))
 		out.eerror("See the make.conf(5) man page for PORTAGE_IONICE_COMMAND usage instructions.")
 
+def setconfig_fallback(root_config):
+	from portage._sets.base import DummyPackageSet
+	from portage._sets.files import WorldSelectedSet
+	from portage._sets.profiles import PackagesSystemSet
+	setconfig = root_config.setconfig
+	setconfig.psets['world'] = DummyPackageSet(atoms=['@selected', '@system'])
+	setconfig.psets['selected'] = WorldSelectedSet(root_config.root)
+	setconfig.psets['system'] = \
+		PackagesSystemSet(root_config.settings.profiles)
+	root_config.sets = setconfig.getSets()
+
+def get_missing_sets(root_config):
+	# emerge requires existence of "world", "selected", and "system"
+	missing_sets = []
+
+	for s in ("selected", "system", "world",):
+		if s not in root_config.sets:
+			missing_sets.append(s)
+
+	return missing_sets
+
+def missing_sets_warning(root_config, missing_sets):
+	if len(missing_sets) > 2:
+		missing_sets_str = ", ".join('"%s"' % s for s in missing_sets[:-1])
+		missing_sets_str += ', and "%s"' % missing_sets[-1]
+	elif len(missing_sets) == 2:
+		missing_sets_str = '"%s" and "%s"' % tuple(missing_sets)
+	else:
+		missing_sets_str = '"%s"' % missing_sets[-1]
+	msg = ["emerge: incomplete set configuration, " + \
+		"missing set(s): %s" % missing_sets_str]
+	if root_config.sets:
+		msg.append("        sets defined: %s" % ", ".join(root_config.sets))
+	msg.append("        This usually means that '%s'" % \
+		(os.path.join(portage.const.GLOBAL_CONFIG_PATH, "sets.conf"),))
+	msg.append("        is missing or corrupt.")
+	for line in msg:
+		writemsg_level(line + "\n", level=logging.ERROR, noiselevel=-1)
+
+def ensure_required_sets(trees):
+	warning_shown = False
+	for root_trees in trees.values():
+		missing_sets = get_missing_sets(root_trees["root_config"])
+		if missing_sets and not warning_shown:
+			warning_shown = True
+			missing_sets_warning(root_trees["root_config"], missing_sets)
+		if missing_sets:
+			setconfig_fallback(root_trees["root_config"])
+
 def expand_set_arguments(myfiles, myaction, root_config):
 
 	if myaction != "search":
@@ -996,6 +1045,8 @@ def emerge_main():
 
 	root_config = trees[settings["ROOT"]]["root_config"]
 
+	ensure_required_sets(trees)
+
 	# only expand sets for actions taking package arguments
 	oldargs = myfiles[:]
 	if myaction in ("clean", "config", "depclean", "info", "prune", "unmerge", None):
-- 
2.26.2