autounmask: Avoid unmasking live versions if possible

Before this patch the allowed changes were:

1. USE
2. USE + ~arch + license
3. USE + ~arch + license + missing keywords + masks

With this patch:

1. USE
2. USE + ~arch + license
3. USE + ~arch + license + missing keywords
4. USE + ~arch + license + masks
5. USE + ~arch + license + missing keywords + masks

This avoids unmasking live versions, which are typically masked
and have missing keywords to be avoided if there is a regular
masked version available.

2 files changed, 71 insertions, 9 deletions

diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index a05c17e93..e4310b480 100644
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -3505,15 +3505,31 @@ class depgraph(object):
 		return True
 
 	class _AutounmaskLevel(object):
-		__slots__ = ("allow_use_changes", "allow_unstable_keywords", "allow_license_changes", "allow_unmasks")
+		__slots__ = ("allow_use_changes", "allow_unstable_keywords", "allow_license_changes", \
+			"allow_missing_keywords", "allow_unmasks")
 
 		def __init__(self):
 			self.allow_use_changes = False
-			self.allow_unstable_keywords = False
 			self.allow_license_changes = False
+			self.allow_unstable_keywords = False
+			self.allow_missing_keywords = False
 			self.allow_unmasks = False
 
 	def _autounmask_levels(self):
+		"""
+		Iterate over the different allowed things to unmask.
+
+		1. USE
+		2. USE + ~arch + license
+		3. USE + ~arch + license + missing keywords
+		4. USE + ~arch + license + masks
+		5. USE + ~arch + license + missing keywords + masks
+
+		Some thoughts:
+			* Do least invasive changes first.
+			* Try unmasking alone before unmasking + missing keywords
+				to avoid -9999 versions if possible
+		"""
 
 		if self._dynamic_config._autounmask is not True:
 			return
@@ -3528,11 +3544,13 @@ class depgraph(object):
 			autounmask_level.allow_unstable_keywords = (not only_use_changes)
 			autounmask_level.allow_license_changes = (not only_use_changes)
 
-			for allow_unmasks in (False, True):
-				if allow_unmasks and (only_use_changes or autounmask_keep_masks):
-					continue
+			for missing_keyword, unmask in ((False,False), (True, False), (False, True), (True, True)):
+
+				if (only_use_changes or autounmask_keep_masks) and (missing_keyword or unmask):
+					break
 
-				autounmask_level.allow_unmasks = allow_unmasks
+				autounmask_level.allow_missing_keywords = missing_keyword
+				autounmask_level.allow_unmasks = unmask
 
 				yield autounmask_level
 
@@ -3634,9 +3652,8 @@ class depgraph(object):
 			#Package has already been unmasked.
 			return True
 
-		#We treat missing keywords in the same way as masks.
 		if (masked_by_unstable_keywords and not autounmask_level.allow_unstable_keywords) or \
-			(masked_by_missing_keywords and not autounmask_level.allow_unmasks) or \
+			(masked_by_missing_keywords and not autounmask_level.allow_missing_keywords) or \
 			(masked_by_p_mask and not autounmask_level.allow_unmasks) or \
 			(missing_licenses and not autounmask_level.allow_license_changes):
 			#We are not allowed to do the needed changes.
diff --git a/pym/portage/tests/resolver/test_autounmask.py b/pym/portage/tests/resolver/test_autounmask.py
index 3da1c2510..46dbab18e 100644
--- a/pym/portage/tests/resolver/test_autounmask.py
+++ b/pym/portage/tests/resolver/test_autounmask.py
@@ -391,7 +391,11 @@ class AutounmaskTestCase(TestCase):
 
 
 	def testAutounmaskKeepMasks(self):
-
+		"""
+		Ensure that we try to use a masked version with keywords before trying
+		masked version with missing keywords (prefer masked regular version
+		over -9999 version).
+		"""
 		ebuilds = {
 			"app-text/A-1": {},
 			}
@@ -427,3 +431,44 @@ class AutounmaskTestCase(TestCase):
 				self.assertEqual(test_case.test_success, True, test_case.fail_msg)
 		finally:
 			playground.cleanup()
+
+
+	def testAutounmask9999(self):
+
+		ebuilds = {
+			"dev-libs/A-1": { },
+			"dev-libs/A-2": { },
+			"dev-libs/A-9999": { "KEYWORDS": "" },
+			"dev-libs/B-1": { "DEPEND": ">=dev-libs/A-2" },
+			"dev-libs/C-1": { "DEPEND": ">=dev-libs/A-3" },
+			}
+
+		profile = {
+			"package.mask":
+				(
+					">=dev-libs/A-2",
+				),
+		}
+
+		test_cases = (
+			ResolverPlaygroundTestCase(
+				["dev-libs/B"],
+				success = False,
+				mergelist = ["dev-libs/A-2", "dev-libs/B-1"],
+				needed_p_mask_changes = set(["dev-libs/A-2"])),
+
+			ResolverPlaygroundTestCase(
+				["dev-libs/C"],
+				success = False,
+				mergelist = ["dev-libs/A-9999", "dev-libs/C-1"],
+				unstable_keywords = set(["dev-libs/A-9999"]),
+				needed_p_mask_changes = set(["dev-libs/A-9999"])),
+			)
+
+		playground = ResolverPlayground(ebuilds=ebuilds, profile=profile)
+		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.cleanup()