In depgraph._serialize_tasks(), verify that an uninstall task has at least one

theoretically mergeable parent before choosing to reverse it's edges.
(trunk r12605)

svn path=/main/branches/2.1.6/; revision=12886

diff --git a/pym/_emerge/__init__.py b/pym/_emerge/__init__.py
index 61a41529dfcdad5c4b8df8c5fd1d23c42feb66da..4109322f94bb4ef5e064a8908f3d92af4eb894dd 100644 (file)
--- a/pym/_emerge/__init__.py
+++ b/pym/_emerge/__init__.py
@@ -6846,6 +6846,41 @@ class depgraph(object):
                        runtime_deps.update(atom for atom in portage_rdepend \
                                if not atom.startswith("!"))
 
+               def gather_deps(ignore_priority, mergeable_nodes,
+                       selected_nodes, node):
+                       """
+                       Recursively gather a group of nodes that RDEPEND on
+                       eachother. This ensures that they are merged as a group
+                       and get their RDEPENDs satisfied as soon as possible.
+                       """
+                       if node in selected_nodes:
+                               return True
+                       if node not in mergeable_nodes:
+                               return False
+                       if node == replacement_portage and \
+                               mygraph.child_nodes(node,
+                               ignore_priority=DepPriority.MEDIUM_SOFT):
+                               # Make sure that portage always has all of it's
+                               # RDEPENDs installed first.
+                               return False
+                       selected_nodes.add(node)
+                       for child in mygraph.child_nodes(node,
+                               ignore_priority=ignore_priority):
+                               if not gather_deps(ignore_priority,
+                                       mergeable_nodes, selected_nodes, child):
+                                       return False
+                       return True
+
+               def ignore_uninst_or_med(priority):
+                       if priority is BlockerDepPriority.instance:
+                               return True
+                       return priority <= DepPriority.MEDIUM
+
+               def ignore_uninst_or_med_soft(priority):
+                       if priority is BlockerDepPriority.instance:
+                               return True
+                       return priority <= DepPriority.MEDIUM_SOFT
+
                ignore_priority_soft_range = [None]
                ignore_priority_soft_range.extend(
                        xrange(DepPriority.MIN, DepPriority.MEDIUM_SOFT + 1))
@@ -6924,28 +6959,6 @@ class depgraph(object):
                        if not selected_nodes:
                                nodes = get_nodes(ignore_priority=DepPriority.MEDIUM)
                                if nodes:
-                                       """Recursively gather a group of nodes that RDEPEND on
-                                       eachother.  This ensures that they are merged as a group
-                                       and get their RDEPENDs satisfied as soon as possible."""
-                                       def gather_deps(ignore_priority,
-                                               mergeable_nodes, selected_nodes, node):
-                                               if node in selected_nodes:
-                                                       return True
-                                               if node not in mergeable_nodes:
-                                                       return False
-                                               if node == replacement_portage and \
-                                                       mygraph.child_nodes(node,
-                                                       ignore_priority=DepPriority.MEDIUM_SOFT):
-                                                       # Make sure that portage always has all of it's
-                                                       # RDEPENDs installed first.
-                                                       return False
-                                               selected_nodes.add(node)
-                                               for child in mygraph.child_nodes(node,
-                                                       ignore_priority=ignore_priority):
-                                                       if not gather_deps(ignore_priority,
-                                                               mergeable_nodes, selected_nodes, child):
-                                                               return False
-                                               return True
                                        mergeable_nodes = set(nodes)
                                        if prefer_asap and asap_nodes:
                                                nodes = asap_nodes
@@ -7003,6 +7016,10 @@ class depgraph(object):
                        if not selected_nodes and not myblocker_uninstalls.is_empty():
                                # An Uninstall task needs to be executed in order to
                                # avoid conflict if possible.
+
+                               mergeable_nodes = get_nodes(
+                                       ignore_priority=ignore_uninst_or_med)
+
                                min_parent_deps = None
                                uninst_task = None
                                for task in myblocker_uninstalls.leaf_nodes():
@@ -7128,10 +7145,19 @@ class depgraph(object):
                                        # best possible choice, but the current algorithm
                                        # is simple and should be near optimal for most
                                        # common cases.
+                                       mergeable_parent = False
                                        parent_deps = set()
                                        for parent in mygraph.parent_nodes(task):
                                                parent_deps.update(mygraph.child_nodes(parent,
                                                        ignore_priority=DepPriority.MEDIUM_SOFT))
+                                               if parent in mergeable_nodes and \
+                                                       gather_deps(ignore_uninst_or_med_soft,
+                                                       mergeable_nodes, set(), parent):
+                                                       mergeable_parent = True
+
+                                       if not mergeable_parent:
+                                               continue
+
                                        parent_deps.remove(task)
                                        if min_parent_deps is None or \
                                                len(parent_deps) < min_parent_deps: