obsutil: maintain a homogenous list when computing successors
In practice, this wasn't a problem because of an internal check for an empty
list, but it avoids the following pytype error:
File "/mnt/c/Users/Matt/hg/mercurial/obsutil.py", line 823, in successorsandmarkers: No attribute 'markers' on List[nothing] [attribute-error]
In Union[Any, List[nothing], _succs]
Differential Revision: https://phab.mercurial-scm.org/D10213
--- a/mercurial/obsutil.py Fri Mar 12 23:28:56 2021 -0500
+++ b/mercurial/obsutil.py Fri Mar 12 21:19:17 2021 -0500
@@ -782,7 +782,7 @@
# closestsuccessors returns an empty list for pruned revisions, remap it
# into a list containing an empty list for future processing
if ssets == []:
- ssets = [[]]
+ ssets = [_succs()]
# Try to recover pruned markers
succsmap = repo.obsstore.successors