depgraph: pull in new virtual slots with --update

This re-implements the fix from commit
21330075f07248765016e104b3ba8216903f1ecb, without introducing the
unwanted behavior reported in bug 382557. This involves checking the
direct dependencies of virtual slot updates to make sure they are all
visible, before pulling them in.

1 files changed, 58 insertions, 11 deletions

diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index 6a04a7971..1e311e8f7 100644
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -2500,24 +2500,36 @@ class depgraph(object):
 			# account for masking and USE settings.
 			_autounmask_backup = self._dynamic_config._autounmask
 			self._dynamic_config._autounmask = False
-			mytrees["pkg_use_enabled"] = self._pkg_use_enabled
+			# backup state for restoration, in case of recursive
+			# calls to this method
+			backup_state = mytrees.copy()
 			try:
+				# clear state from previous call, in case this
+				# call is recursive (we have a backup, that we
+				# will use to restore it later)
+				mytrees.pop("pkg_use_enabled", None)
+				mytrees.pop("parent", None)
+				mytrees.pop("atom_graph", None)
+				mytrees.pop("priority", None)
+
+				mytrees["pkg_use_enabled"] = self._pkg_use_enabled
 				if parent is not None:
-					trees[root]["parent"] = parent
-					trees[root]["atom_graph"] = atom_graph
+					mytrees["parent"] = parent
+					mytrees["atom_graph"] = atom_graph
 				if priority is not None:
-					trees[root]["priority"] = priority
+					mytrees["priority"] = priority
+
 				mycheck = portage.dep_check(depstring, None,
 					pkgsettings, myuse=myuse,
 					myroot=root, trees=trees)
 			finally:
+				# restore state
 				self._dynamic_config._autounmask = _autounmask_backup
-				del mytrees["pkg_use_enabled"]
-				if parent is not None:
-					trees[root].pop("parent")
-					trees[root].pop("atom_graph")
-				if priority is not None:
-					trees[root].pop("priority")
+				mytrees.pop("pkg_use_enabled", None)
+				mytrees.pop("parent", None)
+				mytrees.pop("atom_graph", None)
+				mytrees.pop("priority", None)
+				mytrees.update(backup_state)
 			if not mycheck[0]:
 				raise portage.exception.InvalidDependString(mycheck[1])
 		if parent is None:
@@ -2611,6 +2623,38 @@ class depgraph(object):
 					continue
 				yield atom
 
+	def _virt_deps_visible(self, pkg, ignore_use=False):
+		"""
+		Assumes pkg is a virtual package. Traverses virtual deps recursively
+		and returns True if all deps are visible, False otherwise. This is
+		useful for checking if it will be necessary to expand virtual slots,
+		for cases like bug #382557.
+		"""
+		try:
+			rdepend = self._select_atoms(
+				pkg.root, pkg.metadata.get("RDEPEND", ""),
+				myuse=self._pkg_use_enabled(pkg),
+				parent=pkg, priority=self._priority(runtime=True))
+		except InvalidDependString as e:
+			if not pkg.installed:
+				raise
+			writemsg_level("!!! Invalid RDEPEND in " + \
+				"'%svar/db/pkg/%s/RDEPEND': %s\n" % \
+				(pkg.root, pkg.cpv, e),
+				noiselevel=-1, level=logging.ERROR)
+			return False
+
+		for atoms in rdepend.values():
+			for atom in atoms:
+				if ignore_use:
+					atom = atom.without_use
+				pkg, existing = self._select_package(
+					pkg.root, atom)
+				if pkg is None or not self._pkg_visibility_check(pkg):
+					return False
+
+		return True
+
 	def _get_dep_chain(self, start_node, target_atom=None,
 		unsatisfied_dependency=False):
 		"""
@@ -6540,7 +6584,10 @@ class _dep_check_composite_db(dbapi):
 
 		if pkg is not None and \
 			atom.slot is None and \
-			pkg.cp.startswith("virtual/"):
+			pkg.cp.startswith("virtual/") and \
+			("--update" not in self._depgraph._frozen_config.myopts or
+			not ret or
+			not self._depgraph._virt_deps_visible(pkg, ignore_use=True)):
 			# For new-style virtual lookahead that occurs inside dep_check()
 			# for bug #141118, examine all slots. This is needed so that newer
 			# slots will not unnecessarily be pulled in when a satisfying lower