Backtrack unsatisfied slot-operator, bug #456340.

2 files changed, 115 insertions, 10 deletions

diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index 085ac9bb6..eb88357e1 100644
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -1273,6 +1273,100 @@ class depgraph(object):
 
 		return None
 
+	def _slot_operator_unsatisfied_probe(self, dep):
+
+		if dep.parent.installed and \
+			self._frozen_config.excluded_pkgs.findAtomForPackage(dep.parent,
+			modified_use=self._pkg_use_enabled(dep.parent)):
+			return False
+
+		debug = "--debug" in self._frozen_config.myopts
+
+		for replacement_parent in self._iter_similar_available(dep.parent,
+			dep.parent.slot_atom):
+
+			for atom in replacement_parent.validated_atoms:
+				if not atom.slot_operator == "=" or \
+					atom.blocker or \
+					atom.cp != dep.atom.cp:
+					continue
+
+				# Discard USE deps, we're only searching for an approximate
+				# pattern, and dealing with USE states is too complex for
+				# this purpose.
+				atom = atom.without_use
+
+				pkg, existing_node = self._select_package(dep.root, atom,
+					onlydeps=dep.onlydeps)
+
+				if pkg is not None:
+
+					if debug:
+						msg = []
+						msg.append("")
+						msg.append("")
+						msg.append("slot_operator_unsatisfied_probe:")
+						msg.append("   existing parent package: %s" % dep.parent)
+						msg.append("   existing parent atom: %s" % dep.atom)
+						msg.append("   new parent package: %s" % replacement_parent)
+						msg.append("   new child package:  %s" % pkg)
+						msg.append("")
+						writemsg_level("\n".join(msg),
+							noiselevel=-1, level=logging.DEBUG)
+
+					return True
+
+		if debug:
+			msg = []
+			msg.append("")
+			msg.append("")
+			msg.append("slot_operator_unsatisfied_probe:")
+			msg.append("   existing parent package: %s" % dep.parent)
+			msg.append("   existing parent atom: %s" % dep.atom)
+			msg.append("   new parent package: %s" % None)
+			msg.append("   new child package:  %s" % None)
+			msg.append("")
+			writemsg_level("\n".join(msg),
+				noiselevel=-1, level=logging.DEBUG)
+
+		return False
+
+	def _slot_operator_unsatisfied_backtrack(self, dep):
+
+		parent = dep.parent
+
+		if "--debug" in self._frozen_config.myopts:
+			msg = []
+			msg.append("")
+			msg.append("")
+			msg.append("backtracking due to unsatisfied "
+				"built slot-operator dep:")
+			msg.append("   parent package: %s" % parent)
+			msg.append("   atom: %s" % dep.atom)
+			msg.append("")
+			writemsg_level("\n".join(msg),
+				noiselevel=-1, level=logging.DEBUG)
+
+		backtrack_infos = self._dynamic_config._backtrack_infos
+		config = backtrack_infos.setdefault("config", {})
+
+		# mask unwanted binary packages if necessary
+		masks = {}
+		if not parent.installed:
+			masks.setdefault(parent, {})["slot_operator_mask_built"] = None
+		if masks:
+			config.setdefault("slot_operator_mask_built", {}).update(masks)
+
+		# trigger replacement of installed packages if necessary
+		reinstalls = set()
+		if parent.installed:
+			reinstalls.add((parent.root, parent.slot_atom))
+		if reinstalls:
+			config.setdefault("slot_operator_replace_installed",
+				set()).update(reinstalls)
+
+		self._dynamic_config._need_restart = True
+
 	def _downgrade_probe(self, pkg):
 		"""
 		Detect cases where a downgrade of the given package is considered
@@ -1529,6 +1623,10 @@ class depgraph(object):
 							(dep.parent,
 							self._dynamic_config._runtime_pkg_mask[
 							dep.parent]), noiselevel=-1)
+				elif dep.atom.slot_operator_built and \
+					self._slot_operator_unsatisfied_probe(dep):
+					self._slot_operator_unsatisfied_backtrack(dep)
+					return 1
 				elif not self.need_restart():
 					# Do not backtrack if only USE have to be changed in
 					# order to satisfy the dependency.
diff --git a/pym/portage/tests/resolver/test_slot_operator_unsolved.py b/pym/portage/tests/resolver/test_slot_operator_unsolved.py
index a4962523f..7ae3d9e28 100644
--- a/pym/portage/tests/resolver/test_slot_operator_unsolved.py
+++ b/pym/portage/tests/resolver/test_slot_operator_unsolved.py
@@ -9,11 +9,6 @@ class SlotOperatorUnsolvedTestCase(TestCase):
 	"""
 	Demonstrate bug #456340, where an unsolved circular dependency
 	interacts with an unsatisfied built slot-operator dep.
-
-	The problem here results from poor handling of the unsatisfied built
-	slot operator dep inside _add_dep, where it aborts the graph and tries
-	to backtrack immediately. We really want it to queue a rebuild here,
-	and continue filling out the graph.
 	"""
 	def __init__(self, *args, **kwargs):
 		super(SlotOperatorUnsolvedTestCase, self).__init__(*args, **kwargs)
@@ -31,12 +26,14 @@ class SlotOperatorUnsolvedTestCase(TestCase):
 			},
 			"dev-ruby/rdoc-3.12.1" : {
 				"EAPI": "5",
-				"DEPEND": ">=dev-ruby/hoe-2.7.0",
+				"IUSE": "test",
+				"DEPEND": "test? ( >=dev-ruby/hoe-2.7.0 )",
 			},
 			"dev-ruby/hoe-2.13.0" : {
 				"EAPI": "5",
-				"DEPEND": ">=dev-ruby/rdoc-3.10",
-				"RDEPEND": ">=dev-ruby/rdoc-3.10",
+				"IUSE": "test",
+				"DEPEND": "test? ( >=dev-ruby/rdoc-3.10 )",
+				"RDEPEND": "test? ( >=dev-ruby/rdoc-3.10 )",
 			},
 		}
 
@@ -52,6 +49,10 @@ class SlotOperatorUnsolvedTestCase(TestCase):
 			},
 		}
 
+		user_config = {
+			"make.conf" : ("FEATURES=test",)
+		}
+
 		world = ["net-libs/webkit-gtk", "dev-ruby/hoe"]
 
 		test_cases = (
@@ -59,12 +60,18 @@ class SlotOperatorUnsolvedTestCase(TestCase):
 			ResolverPlaygroundTestCase(
 				["@world"],
 				options = {"--update": True, "--deep": True},
-				success = False),
+				circular_dependency_solutions = {
+					'dev-ruby/hoe-2.13.0': frozenset([frozenset([('test', False)])]),
+					'dev-ruby/rdoc-3.12.1': frozenset([frozenset([('test', False)])])
+				},
+				success = False
+			),
 
 		)
 
 		playground = ResolverPlayground(ebuilds=ebuilds,
-			installed=installed, world=world, debug=False)
+			installed=installed, user_config=user_config,
+			world=world, debug=False)
 		try:
 			for test_case in test_cases:
 				playground.run_TestCase(test_case)