Add support to depgraph._select_atoms() to take a "parent" parameter

and use that to try and avoid unresolvable direct circular dependencies
when necessary. Also, make atom selection more consistent with the
graph to solve some cases of bug #1343. This improves the fix from
bug #141118 to work in cases when a virtual is not yet installed but
it has been pulled into the graph. For example, see the case of
Bug #163801#c17, where we want kaffe to satisfy virtual/jdk-1.4
without an extra jvm being pulled in unnecessarily. (trunk r9901)

svn path=/main/branches/2.1.2/; revision=9903

1 files changed, 38 insertions, 1 deletions

diff --git a/pym/portage.py b/pym/portage.py
index 063acc5f7..3bb6451ee 100644
--- a/pym/portage.py
+++ b/pym/portage.py
@@ -5464,6 +5464,8 @@ def dep_zapdeps(unreduced, reduced, myroot, use_binaries=0, trees=None):
 	other = []
 
 	# Alias the trees we'll be checking availability against
+	parent   = trees[myroot].get("parent")
+	graph_db = trees[myroot].get("graph_db")
 	vardb = None
 	if "vartree" in trees[myroot]:
 		vardb = trees[myroot]["vartree"].dbapi
@@ -5525,8 +5527,43 @@ def dep_zapdeps(unreduced, reduced, myroot, use_binaries=0, trees=None):
 					preferred.append(this_choice)
 				else:
 					preferred_any_slot.append(this_choice)
-			else:
+			elif graph_db is None:
 				possible_upgrades.append(this_choice)
+			else:
+				all_in_graph = True
+				for slot_atom in versions:
+					# New-style virtuals have zero cost to install.
+					if not graph_db.match(slot_atom) and \
+						not slot_atom.startswith("virtual/"):
+						all_in_graph = False
+						break
+				if all_in_graph:
+					if parent is None:
+						preferred.append(this_choice)
+					else:
+						# Check if the atom would result in a direct circular
+						# dependency and try to avoid that if it seems likely
+						# to be unresolvable.
+						cpv_slot_list = [parent.cpv_slot]
+						circular_atom = None
+						for atom in atoms:
+							if "!" == atom[:1]:
+								continue
+							if vardb.match(atom):
+								# If the atom is satisfied by an installed
+								# version then it's not a circular dep.
+								continue
+							if dep_getkey(atom) != parent.cp:
+								continue
+							if match_from_list(atom, cpv_slot_list):
+								circular_atom = atom
+								break
+						if circular_atom is None:
+							preferred.append(this_choice)
+						else:
+							other.append(this_choice)
+				else:
+					possible_upgrades.append(this_choice)
 		else:
 			other.append(this_choice)