[gentoo-portage-dev] [PATCH] dep_zapdeps: fix virtual/rust handling (bug 645416)

[Zac Medico]

Fix the code from bug 643974 to set the installed_downgrade flag only
if the selected newer package is either installed or in the graph. This
is currently needed for appropriate handling of virtual/rust-1.19.0,
since there's an upgrade to dev-lang/rust-1.23.0 available which may
not be desired since it would mean that dev-lang/rust-bin-1.19.0 has
to be installed in order to satisfy virtual/rust-1.19.0:

 || ( =dev-lang/rust-1.19.0* =dev-lang/rust-bin-1.19.0* )

So, the rust-bin choice is desirable only if the rust-1.23.0 package is
already installed or in the graph.

Fixes: 86ba22da7a2f ("dep_zapdeps: install new package, allow upgrade (bug 643974)")
Bug: https://bugs.gentoo.org/645416
---
 pym/portage/dep/dep_check.py                       | 10 ++--
 .../tests/resolver/test_or_upgrade_installed.py    | 59 ++++++++++++++++++++++
 2 files changed, 66 insertions(+), 3 deletions(-)

diff --git a/pym/portage/dep/dep_check.py b/pym/portage/dep/dep_check.py
index c56f545ec..7e5a3186e 100644
--- a/pym/portage/dep/dep_check.py
+++ b/pym/portage/dep/dep_check.py
@@ -463,11 +463,15 @@ def dep_zapdeps(unreduced, reduced, myroot, use_binaries=0, trees=None):
 						avail_pkg = avail_pkg_use
 					avail_slot = Atom("%s:%s" % (atom.cp, avail_pkg.slot))
 
-			if downgrade_probe is not None:
+			if downgrade_probe is not None and graph is not None:
 				highest_in_slot = mydbapi_match_pkgs(avail_slot)
+				highest_in_slot = (highest_in_slot[-1]
+					if highest_in_slot else None)
 				if (avail_pkg and highest_in_slot and
-					avail_pkg < highest_in_slot[-1] and
-					not downgrade_probe(avail_pkg)):
+					avail_pkg < highest_in_slot and
+					not downgrade_probe(avail_pkg) and
+					(highest_in_slot.installed or
+					highest_in_slot in graph)):
 					installed_downgrade = True
 
 			slot_map[avail_slot] = avail_pkg
diff --git a/pym/portage/tests/resolver/test_or_upgrade_installed.py b/pym/portage/tests/resolver/test_or_upgrade_installed.py
index 6e01d321d..7018e08de 100644
--- a/pym/portage/tests/resolver/test_or_upgrade_installed.py
+++ b/pym/portage/tests/resolver/test_or_upgrade_installed.py
@@ -99,3 +99,62 @@ class OrUpgradeInstalledTestCase(TestCase):
 		finally:
 			playground.debug = False
 			playground.cleanup()
+
+	def testVirtualRust(self):
+		ebuilds = {
+			'dev-lang/rust-1.19.0': {},
+			'dev-lang/rust-1.23.0': {},
+			'dev-lang/rust-bin-1.19.0': {},
+			'virtual/rust-1.19.0': {
+				'RDEPEND': '|| ( =dev-lang/rust-1.19.0* =dev-lang/rust-bin-1.19.0* )'
+			},
+		}
+
+		installed = {
+			'dev-lang/rust-1.19.0': {},
+			'virtual/rust-1.19.0': {
+				'RDEPEND': '|| ( =dev-lang/rust-1.19.0* =dev-lang/rust-bin-1.19.0* )'
+			},
+		}
+
+		world = ['virtual/rust']
+
+		test_cases = (
+			# Test bug 645416, where rust-bin-1.19.0 was pulled in
+			# inappropriately due to the rust-1.23.0 update being
+			# available.
+			ResolverPlaygroundTestCase(
+				['virtual/rust'],
+				options={'--update': True, '--deep': True},
+				success=True,
+				mergelist=[]
+			),
+			# Test upgrade to rust-1.23.0, which is only possible
+			# if rust-bin-1.19.0 is installed in order to satisfy
+			# virtual/rust-1.19.0.
+			ResolverPlaygroundTestCase(
+				['=dev-lang/rust-1.23.0', 'virtual/rust'],
+				options={'--update': True, '--deep': True},
+				all_permutations=True,
+				success=True,
+				ambiguous_merge_order=True,
+				mergelist=(
+					(
+						'dev-lang/rust-1.23.0',
+						'dev-lang/rust-bin-1.19.0',
+					),
+				),
+			),
+		)
+
+		playground = ResolverPlayground(debug=False,
+			ebuilds=ebuilds, installed=installed, world=world)
+
+		try:
+			for test_case in test_cases:
+				playground.run_TestCase(test_case)
+				self.assertEqual(test_case.test_success, True,
+					test_case.fail_msg)
+		finally:
+			playground.debug = False
+			playground.cleanup()
-- 
2.13.6