Always create a new SourcePackage

When an item is migrated to the target suite, always create a new
SourcePackage object with a separate binaries list (independent from the list
in the source suite). That list is updated for every binary that is added,
updated or removed. This should ensure consistent source package information
in the target suite.

The undo code doesn't need to be updated for this, because the old
SourcePackage object is put back on undo, with the old binary list.

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

britney2/migration.py

@@ -1,5 +1,6 @@
 import apt_pkg
 import contextlib
+import copy
 
 from britney2.transaction import MigrationTransactionState
 from britney2.utils import (
@@ -246,14 +247,21 @@ class MigrationManager(object):
 
         sources_t = target_suite.sources
         # Handle the source package
-        if item.architecture == 'source':
-            undo['sources'][source_name] = sources_t.get(source_name)
+        old_source = sources_t.get(source_name)
 
-            # add/update the source package
-            if item.is_removal:
-                del sources_t[source_name]
+        # add/update the source package
+        if item.is_removal and item.architecture == 'source':
+            del sources_t[source_name]
+        else:
+            # always create a copy of the SourcePackage object
+            sources_t[source_name] = copy.copy(source_suite.sources[source_name])
+            if old_source is not None:
+                # always create a new list of binaries
+                sources_t[source_name].binaries = copy.copy(old_source.binaries)
             else:
-                sources_t[source_name] = source_suite.sources[source_name]
+                sources_t[source_name].binaries = list()
+
+        undo['sources'][source_name] = old_source
 
         eqv_set = compute_eqv_set(pkg_universe, updates, rms)
 
@@ -281,6 +289,10 @@ class MigrationManager(object):
                 provides_t_a[provided_pkg].remove((binary, prov_version))
                 if not provides_t_a[provided_pkg]:
                     del provides_t_a[provided_pkg]
+            # for source removal, the source is already gone
+            if source_name in sources_t:
+                if rm_pkg_id in sources_t[source_name].binaries:
+                    sources_t[source_name].binaries.remove(rm_pkg_id)
             # finally, remove the binary package
             del binaries_t_a[binary]
             target_suite.remove_binary(rm_pkg_id)
@@ -333,6 +345,9 @@ class MigrationManager(object):
                 binaries_t_a[binary] = new_pkg_data
                 target_suite.add_binary(updated_pkg_id)
                 updated_binaries.add(updated_pkg_id)
+                # add the binary to the source package
+                if updated_pkg_id not in sources_t[source_name].binaries:
+                    sources_t[source_name].binaries.append(updated_pkg_id)
                 # register new provided packages
                 for provided_pkg, prov_version, _ in new_pkg_data.provides:
                     key = (provided_pkg, parch)