_show_circular_deps: Ignore solution that violate use dpendencies specified by parent...

diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index 52d3a9d4a3d672fc23f18d5847e1beaf8f54c3da..7be8db139628434e91dc73f4d6980b55b8077218 100644 (file)
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -4101,8 +4101,9 @@ class depgraph(object):
 
        def _show_circular_deps(self, mygraph):
                shortest_cycle = None
-               for cycle in mygraph.get_cycles(ignore_priority=DepPrioritySatisfiedRange.ignore_medium_soft):
-                       if not shortest_cycle or len(shortest_cycle) > len(cycle):
+               cycles = mygraph.get_cycles(ignore_priority=DepPrioritySatisfiedRange.ignore_medium_soft)
+               for cycle in cycles:
+                       if not shortest_cycle or len(shortest_cycle) < len(cycle):
                                shortest_cycle = cycle
 
                # Display the USE flags that are enabled on nodes that are part
@@ -4152,6 +4153,7 @@ class depgraph(object):
                                parent_atoms = self._dynamic_config._parent_atoms.get(pkg)
                                for ppkg, atom in parent_atoms:
                                        if ppkg == parent:
+                                               changed_parent = ppkg
                                                parent_atom = atom.unevaluated_atom
                                                break
                                affecting_use = portage.dep.extract_affecting_use(dep, parent_atom)
@@ -4201,7 +4203,6 @@ class depgraph(object):
                                                        solutions.add(frozenset(solution))
                                                if not _next_use_state(use_state):
                                                        break
-
                                        for solution in solutions:
                                                ignore_solution = False
                                                for other_solution in solutions:
@@ -4212,6 +4213,31 @@ class depgraph(object):
                                                if ignore_solution:
                                                        continue
 
+                                               #Check if a USE change conflicts with use requirements of the parents.
+                                               #If a requiremnet is hard, ignore the suggestion.
+                                               #If the requirment is conditional, warn the user that other changes might be needed.
+                                               followup_change = False
+                                               parent_parent_atoms = self._dynamic_config._parent_atoms.get(changed_parent)
+                                               for ppkg, atom in parent_parent_atoms:
+                                                       atom = atom.unevaluated_atom
+                                                       if not atom.use:
+                                                               continue
+
+                                                       for flag in solution:
+                                                               flag = flag[1:] #flag has a +/- prefix
+                                                               if flag in atom.use.enabled \
+                                                                       or flag in atom.use.disabled:
+                                                                       ignore_solution = True
+                                                                       break
+                                                               elif atom.use.conditional and flag in atom.use.conditional:
+                                                                       followup_change = True
+
+                                                       if ignore_solution:
+                                                               break
+
+                                               if ignore_solution:
+                                                       continue
+
                                                changes = []
                                                for flag in solution:
                                                        if flag.startswith("+"):
@@ -4219,8 +4245,11 @@ class depgraph(object):
                                                        else:
                                                                changes.append(colorize("blue", flag))
 
-                                               suggestions.append("- %s (Change USE: %s)\n" \
-                                                       % (parent.cpv, " ".join(changes)))
+                                               msg = "- %s (Change USE: %s)\n" \
+                                                       % (parent.cpv, " ".join(changes))
+                                               if followup_change:
+                                                       msg += " (This change might require USE changes on parent packages.)"
+                                               suggestions.append(msg)
 
                                indent += " "
 
@@ -4240,7 +4269,11 @@ class depgraph(object):
                                        " the following changes:\n", noiselevel=-1)
                        writemsg("".join(suggestions), noiselevel=-1)
                        writemsg("\nNote that this change can be reverted, once the package has" + \
-                               " been installed.\n\n", noiselevel=-1)
+                               " been installed.\n", noiselevel=-1)
+                       if len(cycles) > 3:
+                               writemsg("\nNote that the dependency graph contains a lot of cycles.\n" + \
+                                       "Several changes might be required to resolve all cycles.\n" + \
+                                       "Temporarily changing some use flag for all packages might be the better option.\n", noiselevel=-1)
                else:
                        writemsg("\n", noiselevel=-1)
                        writemsg(prefix + "Note that circular dependencies " + \