--- pym/portage.py	(revision 6780)
+++ pym/portage.py	(revision 6785)
@@ -1693,6 +1693,7 @@ 
 		cp = dep_getkey(mycpv)
 		cpv_slot = self.mycpv
 		pkginternaluse = ""
+		iuse = ""
 		if mydb:
 			slot, iuse = mydb.aux_get(self.mycpv, ["SLOT", "IUSE"])
 			cpv_slot = "%s:%s" % (self.mycpv, slot)
@@ -1753,6 +1754,9 @@ 
 			has_changed = True
 		self.configdict["pkg"]["PKGUSE"] = self.puse[:] # For saving to PUSE file
 		self.configdict["pkg"]["USE"]    = self.puse[:] # this gets appended to USE
+		if iuse != self.configdict["pkg"].get("IUSE",""):
+			self.configdict["pkg"]["IUSE"] = iuse
+			has_changed = True
 		# CATEGORY is essential for doebuild calls
 		self.configdict["pkg"]["CATEGORY"] = mycpv.split("/")[0]
 		if has_changed:
@@ -1955,10 +1959,10 @@ 
 		usesplit = [ x for x in myflags if \
 			x not in self.usemask]
 
-		usesplit.sort()
-
 		# Use the calculated USE flags to regenerate the USE_EXPAND flags so
 		# that they are consistent.
+		iuse = self.configdict["pkg"].get("IUSE","").split()
+		iuse = set([ x.lstrip("+-") for x in iuse ])
 		for var in use_expand:
 			prefix = var.lower() + "_"
 			prefix_len = len(prefix)
@@ -1969,11 +1973,34 @@ 
 			# like LINGUAS.
 			var_split = [ x for x in var_split if x in expand_flags ]
 			var_split.extend(expand_flags.difference(var_split))
-			if var_split or var in self:
+			if (var_split or var in self) and \
+				"*" not in var_split:
 				# Don't export empty USE_EXPAND vars unless the user config
 				# exports them as empty.  This is required for vars such as
 				# LINGUAS, where unset and empty have different meanings.
 				self[var] = " ".join(var_split)
+			elif "*" in var_split:
+				# * means to enable everything in IUSE that's not masked
+				filtered_split = []
+				for x in var_split:
+					if x == "*":
+						continue
+					if (prefix + x) in iuse:
+						filtered_split.append(x)
+				var_split = filtered_split
+				for x in iuse:
+					if x.startswith(prefix) and x not in self.usemask:
+						suffix = x[prefix_len:]
+						if suffix in var_split:
+							continue
+						var_split.append(suffix)
+						usesplit.append(x)
+				if var_split:
+					self[var] = " ".join(var_split)
+				elif var in self:
+					# ebuild.sh will see this and unset the variable so
+					# that things like LINGUAS work properly
+					self[var] = "*"
 
 		# Pre-Pend ARCH variable to USE settings so '-*' in env doesn't kill arch.
 		if self.configdict["defaults"].has_key("ARCH"):
@@ -1981,6 +2008,7 @@ 
 				if self.configdict["defaults"]["ARCH"] not in usesplit:
 					usesplit.insert(0,self.configdict["defaults"]["ARCH"])
 
+		usesplit.sort()
 		self.configlist[-1]["USE"]= " ".join(usesplit)
 
 		self.already_in_regenerate = 0
--- bin/ebuild.sh	(revision 6780)
+++ bin/ebuild.sh	(revision 6785)
@@ -1585,6 +1585,11 @@ 
 	done
 	export IUSE=${iuse_temp}
 	unset iuse_temp
+	# unset USE_EXPAND variables that contain only the special "*" token
+	for x in ${USE_EXPAND} ; do
+		[ "${!x}" == "*" ] && unset ${x}
+	done
+	unset x
 	# Lock the dbkey variables after the global phase
 	declare -r DEPEND RDEPEND SLOT SRC_URI RESTRICT HOMEPAGE LICENSE DESCRIPTION
 	declare -r KEYWORDS INHERITED IUSE PDEPEND PROVIDE