In dblink.treewalk(), handle the case where the current cpv is already installed but it has a different slot (multislot or unapplied slotmove). (branches/2.1.2 r6834)

svn path=/main/branches/2.1.2.9/; revision=7532
diff --git a/pym/portage.py b/pym/portage.py
index 44de57f..55d0f79 100644
--- a/pym/portage.py
+++ b/pym/portage.py
@@ -7435,6 +7435,11 @@
 
 		slot_matches = self.vartree.dbapi.match(
 			"%s:%s" % (self.mysplit[0], self.settings["SLOT"]))
+		if self.mycpv not in slot_matches and \
+			self.vartree.dbapi.cpv_exists(self.mycpv):
+			# handle multislot or unapplied slotmove
+			slot_matches.append(self.mycpv)
+
 		if slot_matches:
 			# Used by self.isprotected().
 			max_cpv = None