emerge: add --complete-graph-if-new-ver < y | n >

Trigger the --complete-graph behavior if an installed package version will
change (upgrade or downgrade). This option is enabled by default.

5 files changed, 93 insertions, 12 deletions

diff --git a/man/emerge.1 b/man/emerge.1
index 6d9ce4c44..4ec025127 100644
--- a/man/emerge.1
+++ b/man/emerge.1
@@ -376,6 +376,10 @@ be updated than would have otherwise been updated with the option disabled.
 Using \fB\-\-with\-bdeps=y\fR together with \fB\-\-complete\-graph\fR makes
 the graph as complete as possible.
 .TP
+.BR "\-\-complete\-graph\-if\-new\-ver < y | n >"
+Trigger the \fB\-\-complete\-graph\fR behavior if an installed package
+version will change (upgrade or downgrade). This option is enabled by default.
+.TP
 .BR \-\-config\-root=DIR
 Set the \fBPORTAGE_CONFIGROOT\fR environment variable.
 .TP
diff --git a/pym/_emerge/create_depgraph_params.py b/pym/_emerge/create_depgraph_params.py
index 44dceda37..221c440ef 100644
--- a/pym/_emerge/create_depgraph_params.py
+++ b/pym/_emerge/create_depgraph_params.py
@@ -37,6 +37,12 @@ def create_depgraph_params(myopts, myaction):
 	deep = myopts.get("--deep")
 	if deep is not None and deep != 0:
 		myparams["deep"] = deep
+
+	complete_if_new_ver = \
+		myopts.get("--complete-graph-if-new-ver")
+	if complete_if_new_ver is not None:
+		myparams["complete_if_new_ver"] = complete_if_new_ver
+
 	if ("--complete-graph" in myopts or "--rebuild-if-new-rev" in myopts or
 		"--rebuild-if-new-ver" in myopts or "--rebuild-if-unbuilt" in myopts):
 		myparams["complete"] = True
diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index ffa7e167e..8121f68bc 100644
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -4145,11 +4145,10 @@ class depgraph(object):
 			"recurse" not in self._dynamic_config.myparams:
 			return 1
 
-		if "complete" not in self._dynamic_config.myparams:
-			# Automatically enable complete mode if there are any
-			# downgrades, since they often break dependencies
-			# (like in bug #353613).
-			have_downgrade = False
+		if "complete" not in self._dynamic_config.myparams and \
+			self._dynamic_config.myparams.get("complete_if_new_ver", "y") == "y":
+			# Enable complete mode if an installed package version will change.
+			version_change = False
 			for node in self._dynamic_config.digraph:
 				if not isinstance(node, Package) or \
 					node.operation != "merge":
@@ -4157,16 +4156,15 @@ class depgraph(object):
 				vardb = self._frozen_config.roots[
 					node.root].trees["vartree"].dbapi
 				inst_pkg = vardb.match_pkgs(node.slot_atom)
-				if inst_pkg and inst_pkg[0] > node:
-					have_downgrade = True
+				if inst_pkg and (inst_pkg[0] > node or inst_pkg[0] < node):
+					version_change = True
 					break
 
-			if have_downgrade:
+			if version_change:
 				self._dynamic_config.myparams["complete"] = True
-			else:
-				# Skip complete graph mode, in order to avoid consuming
-				# enough time to disturb users.
-				return 1
+
+		if "complete" not in self._dynamic_config.myparams:
+			return 1
 
 		self._load_vdb()
 
diff --git a/pym/_emerge/main.py b/pym/_emerge/main.py
index 96a6cfadb..d2fc0ac5f 100644
--- a/pym/_emerge/main.py
+++ b/pym/_emerge/main.py
@@ -588,6 +588,7 @@ def parse_opts(tmpcmdline, silent=False):
 	])
 
 	longopt_aliases = {"--cols":"--columns", "--skip-first":"--skipfirst"}
+	y_or_n = ("y", "n")
 	true_y_or_n = ("True", "y", "n")
 	true_y = ("True", "y")
 	argument_options = {
@@ -659,6 +660,12 @@ def parse_opts(tmpcmdline, silent=False):
 			"choices" : true_y_or_n
 		},
 
+		"--complete-graph-if-new-ver": {
+			"help"    : "trigger --complete-graph behavior if an installed package version will change (upgrade or downgrade)",
+			"type"    : "choice",
+			"choices" : y_or_n
+		},
+
 		"--deep": {
 
 			"shortopt" : "-D",
diff --git a/pym/portage/tests/resolver/test_complete_graph.py b/pym/portage/tests/resolver/test_complete_graph.py
new file mode 100644
index 000000000..07206430e
--- /dev/null
+++ b/pym/portage/tests/resolver/test_complete_graph.py
@@ -0,0 +1,66 @@
+# Copyright 2011 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+from portage.tests import TestCase
+from portage.tests.resolver.ResolverPlayground import (ResolverPlayground,
+	ResolverPlaygroundTestCase)
+
+class CompleteGraphTestCase(TestCase):
+
+	def testCompleteGraphVersionChange(self):
+		"""
+		Prevent reverse dependency breakage triggered by version changes.
+		"""
+
+		ebuilds = {
+			"sys-libs/x-0.1": {},
+			"sys-libs/x-1": {},
+			"sys-libs/x-2": {},
+			"sys-apps/a-1": {"RDEPEND" : ">=sys-libs/x-1 <sys-libs/x-2"},
+		}
+
+		installed = {
+			"sys-libs/x-1": {},
+			"sys-apps/a-1": {"RDEPEND" : ">=sys-libs/x-1 <sys-libs/x-2"},
+		}
+
+		world = ["sys-apps/a"]
+
+		test_cases = (
+			ResolverPlaygroundTestCase(
+				[">=sys-libs/x-2"],
+				options = {"--complete-graph-if-new-ver" : "n"},
+				mergelist = ["sys-libs/x-2"],
+				success = True,
+			),
+			ResolverPlaygroundTestCase(
+				[">=sys-libs/x-2"],
+				options = {"--complete-graph-if-new-ver" : "y"},
+				mergelist = ["sys-libs/x-2"],
+				slot_collision_solutions = [],
+				success = False,
+			),
+			ResolverPlaygroundTestCase(
+				["<sys-libs/x-1"],
+				options = {"--complete-graph-if-new-ver" : "n"},
+				mergelist = ["sys-libs/x-0.1"],
+				success = True,
+			),
+			ResolverPlaygroundTestCase(
+				["<sys-libs/x-1"],
+				options = {"--complete-graph-if-new-ver" : "y"},
+				mergelist = ["sys-libs/x-0.1"],
+				slot_collision_solutions = [],
+				success = False,
+			),
+		)
+
+		playground = ResolverPlayground(ebuilds=ebuilds,
+			installed=installed, world=world, debug=False)
+
+		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()