treewalk: fix plib_collisions with same cpv

diff --git a/pym/portage/dbapi/vartree.py b/pym/portage/dbapi/vartree.py
index cdae3407758e867c31ba41de340e9e6ead1ed82d..13d9ab2207878616023315cc0f9586df7dbe6cc4 100644 (file)
--- a/pym/portage/dbapi/vartree.py
+++ b/pym/portage/dbapi/vartree.py
@@ -3468,14 +3468,20 @@ class dblink(object):
                                for cpv, paths in plib_collisions.items():
                                        if cpv not in plib_dict:
                                                continue
-                                       if cpv == self.mycpv:
-                                               continue
-                                       has_vdb_entry = True
-                                       try:
-                                               slot, counter = self.vartree.dbapi.aux_get(
-                                                       cpv, ["SLOT", "COUNTER"])
-                                       except KeyError:
-                                               has_vdb_entry = False
+                                       has_vdb_entry = False
+                                       if cpv != self.mycpv:
+                                               # If we've replaced another instance with the
+                                               # same cpv then the vdb entry no longer belongs
+                                               # to it, so we'll have to get the slot and couter
+                                               # from plib_registry._data instead.
+                                               try:
+                                                       slot, counter = self.vartree.dbapi.aux_get(
+                                                               cpv, ["SLOT", "COUNTER"])
+                                                       has_vdb_entry = True
+                                               except KeyError:
+                                                       pass
+
+                                       if not has_vdb_entry:
                                                # It's possible for previously unmerged packages
                                                # to have preserved libs in the registry, so try
                                                # to retrieve the slot and counter from there.