Comment some more on the significance of passing the graph_db and parent

into depgraph._select_atoms() to solve some cases of bug #1343 while
avoiding unresolvable direct circular dependencies.

svn path=/main/trunk/; revision=9904

diff --git a/pym/_emerge/__init__.py b/pym/_emerge/__init__.py
index e5c9b0ca9c546be932e835d0e38b84d894f35c86..ab1bb3543a7fdddc45db785d67c6d238a43c9c24 100644 (file)
--- a/pym/_emerge/__init__.py
+++ b/pym/_emerge/__init__.py
@@ -1609,7 +1609,6 @@ class depgraph(object):
                                pass
                        filtered_tree.dbapi = self._dep_check_composite_db(self, myroot)
                        self._filtered_trees[myroot]["porttree"] = filtered_tree
-                       self._filtered_trees[myroot]["graph_db"] = graph_tree.dbapi
 
                        # Passing in graph_tree as the vartree here could lead to better
                        # atom selections in some cases by causing atoms for packages that
@@ -1620,6 +1619,14 @@ class depgraph(object):
                        # gwydion-dylan-bin. In case gwydion-dylan is not yet installed,
                        # gwydion-dylan-bin needs to be selected in order to avoid a
                        # an unresolvable direct circular dependency.
+                       #
+                       # To solve the problem described above, pass in "graph_db" so that
+                       # packages that have been added to the graph are distinguishable
+                       # from other available packages and installed packages. Also, pass
+                       # the parent package into self._select_atoms() calls so that
+                       # unresolvable direct circular dependencies can be detected and
+                       # avoided when possible.
+                       self._filtered_trees[myroot]["graph_db"] = graph_tree.dbapi
                        self._filtered_trees[myroot]["vartree"] = self.trees[myroot]["vartree"]
 
                        dbs = []