Check version of cruft removal item

If the cruft removal item has a different version than the binary currently in
testing, then the cruft item was replaced since it was added, or it was added
in error. In this case, the item should not be processed.

Signed-off-by: Ivo De Decker <ivodd@debian.org>

britney.py

@@ -878,10 +878,15 @@ class Britney(object):
                                 target_suite.check_suite_source_pkg_consistency('iter_packages after commit')
                             nuninst_last_accepted = nuninst_after
                             for cruft_item in new_cruft:
+                                try:
                                     _, updates, rms, _ = mm.compute_groups(cruft_item)
                                     result = (cruft_item, frozenset(updates), frozenset(rms))
                                     group_info[cruft_item] = result
-                            worklist.extend([x] for x in new_cruft)
+                                    worklist.append([cruft_item])
+                                except MigrationConstraintException as e:
+                                    output_logger.info(
+                                        "    got exception adding cruft item %s to list: %s" %
+                                        (cruft_item.uvname, repr(e)))
                             rescheduled_packages.extend(maybe_rescheduled_packages)
                             maybe_rescheduled_packages.clear()
                         else:

britney2/migration.py

@@ -112,6 +112,12 @@ class MigrationManager(object):
         else:
             assert item_package in binaries_t[item.architecture]
             pkg_id = binaries_t[item.architecture][item_package].pkg_id
+            binary, ver, parch = pkg_id
+            if ver != item.version:
+                raise MigrationConstraintException(
+                    "trying cruft removal item %s, while %s has %s/%s on %s" % (
+                        item, target_suite.name,
+                        binary, ver, parch))
             source_name = binaries_t[item.architecture][item_package].source
             rms = {pkg_id}
             smoothbins = set()