Allow multislot packages to be added to the world file

via --noreplace. Having these atoms in the world file
will trigger recommendations to run emaint in some
cases, like when running `emerge -e world`. The atoms
need to be in the world file to prevent multislot
packages from being removed by --depclean though.
(trunk r8436)

Bug #198129 - Prevent SLOT atoms like  sys-devel/binutils:0
from being inappropriately recorded in the world file when
USE=multislot is enabled.
(trunk r8437:8439)

svn path=/main/branches/2.1.2/; revision=8440

1 files changed, 30 insertions, 7 deletions

diff --git a/bin/emerge b/bin/emerge
index b9bebda6b..2c79af69e 100755
--- a/bin/emerge
+++ b/bin/emerge
@@ -735,17 +735,40 @@ def create_world_atom(pkg_key, metadata, args_set, root_config):
 		# If the user gave a specific atom, store it as a
 		# slot atom in the world file.
 		slot_atom = "%s:%s" % (cp, metadata["SLOT"])
-		# First verify the slot is in the portage tree to avoid
-		# adding a bogus slot like that produced by multislot.
-		if portdb.match(slot_atom):
-			# Now verify that the argument is precise enough to identify a
-			# specific slot.
-			matches = portdb.match(arg_atom)
+
+		# For USE=multislot, there are a couple of cases to
+		# handle here:
+		#
+		# 1) SLOT="0", but the real SLOT spontaneously changed to some
+		#    unknown value, so just record an unslotted atom.
+		#
+		# 2) SLOT comes from an installed package and there is no
+		#    matching SLOT in the portage tree.
+		#
+		# Make sure that the slot atom is available in either the
+		# portdb or the vardb, since otherwise the user certainly
+		# doesn't want the SLOT atom recorded in the world file
+		# (case 1 above).  If it's only available in the vardb,
+		# the user may be trying to prevent a USE=multislot
+		# package from being removed by --depclean (case 2 above).
+
+		mydb = portdb
+		if not portdb.match(slot_atom):
+			# SLOT seems to come from an installed multislot package
+			mydb = vardb
+		# If there is no installed package matching the SLOT atom,
+		# it probably changed SLOT spontaneously due to USE=multislot,
+		# so just record an unslotted atom.
+		if vardb.match(slot_atom):
+			# Now verify that the argument is precise
+			# enough to identify a specific slot.
+			matches = mydb.match(arg_atom)
 			matched_slots = set()
 			for cpv in matches:
-				matched_slots.add(portdb.aux_get(cpv, ["SLOT"])[0])
+				matched_slots.add(mydb.aux_get(cpv, ["SLOT"])[0])
 			if len(matched_slots) == 1:
 				new_world_atom = slot_atom
+
 	if new_world_atom == sets["world"].findAtomForPackage(pkg_key, metadata):
 		# Both atoms would be identical, so there's nothing to add.
 		return None