[migration-tools] Always release source version with updated release …

…increment instead of last_version. (ros#32112)

* Always release source version and source increment + 1 instead of last_version.

When performing the Rolling platform migration several repositories had bloom releases which were not committed to the distribution file at the time of the source ref.
As a result the `last_version` entries for those repositories did not match the release version in the source distribution during migration.
Since the migration tool was using the last_release in order to handle any releases that were not hard coded to a specific version and/or release tag this created a split between what was performed by git-bloom-release during migration and what was configured in the resulting distribution file.

One example is the ros2_control repository which had a 2.2.0-1 release made in ros2-gbp/ros2_control-release@7504ac3 but which never received a rosdistro PR.
Thus the migration tool released 2.2.0-2 based on the last_release information in the tracks file but the source distribution was anticipating 2.1.0-2.

Of the changes in this commit I am most hesitant about the release_increment handling since this script will eventually generate and force push updated release artifacts and if in a similar situation a 2.1.0-2 was released but not published in the source distribution file its artifacts would be clobbered where they overlapped with the migration-tool's own 2.1.0-2.
However I don't have a method of resolving that situation without searching each release repository's artifacts for a full list of release increments associated with a version.

* Increment the greater between the source distribution increment and current release increment.

Reduce the likelihood that the migration will clobber existing release tags by incrementing the greater between the source distribution increment and the current release increment in the Bloom track.
There are still situations where a release could be clobbered which has been documented but left unhandled.


Co-authored-by: Scott K Logan <logans@cottsay.net>

migration-tools/migrate-rosdistro.py

@@ -183,20 +183,35 @@ def write_tracks_file(tracks, commit_msg=None):
         # interactivity and :{auto} may result in a previously unreleased tag
         # on the development branch being released for the first time.
         if dest_track['version'] in [':{ask}', ':{auto}']:
-            # Override the version for this release to guarantee the same version is released.
+            # Override the version for this release to guarantee the same version from our
+            # source distribution is released.
             dest_track['version_saved'] = dest_track['version']
-            dest_track['version'] = dest_track['last_version']
-            write_tracks_file(tracks, f'Update {args.dest} track to release exactly last-released version.')
+            source_version, source_inc = source_distribution.repositories[repo_name].release_repository.version.split('-')
+            dest_track['version'] = source_version
+            write_tracks_file(tracks, f'Update {args.dest} track to release the same version as the source distribution.')
 
         if dest_track['release_tag'] == ':{ask}' and 'last_release' in dest_track:
             # Override the version for this release to guarantee the same version is released.
             dest_track['release_tag_saved'] = dest_track['release_tag']
             dest_track['release_tag'] = dest_track['last_release']
             write_tracks_file(tracks, f'Update {args.dest} track to release exactly last-released tag.')
 
+        # Update release increment for the upcoming release.
+        # We increment whichever is greater between the source distribution's
+        # release increment and the release increment in the bloom track since
+        # there may be releases that were not committed to the source
+        # distribution.
+        # This heuristic does not fully cover situations where the version in
+        # the source distribution and the version in the release track differ.
+        # In that case it is still possible for this tool to overwrite a
+        # release increment if the greatest increment of the source version is
+        # not in the source distribution and does not match the version
+        # currently in the release track.
+        release_inc = str(max(int(source_inc), int(dest_track['release_inc'])) + 1)
+
         # Bloom will not run with multiple remotes.
         subprocess.check_call(['git', 'remote', 'remove', 'oldorigin'])
-        subprocess.check_call(['git', 'bloom-release', '--non-interactive', '--unsafe', args.dest], env=os.environ)
+        subprocess.check_call(['git', 'bloom-release', '--non-interactive', '--release-increment', release_inc, '--unsafe', args.dest], env=os.environ)
         subprocess.check_call(['git', 'push', 'origin', '--all', '--force'])
         subprocess.check_call(['git', 'push', 'origin', '--tags', '--force'])
         subprocess.check_call(['git', 'checkout', 'master'])