mercurial/shelve.py

--- a/mercurial/shelve.py	Mon Nov 16 22:38:36 2020 -0800
+++ b/mercurial/shelve.py	Mon Nov 16 21:28:42 2020 -0800
@@ -564,6 +564,10 @@
                 scmutil.movedirstate(repo, parent, match)
         else:
             hg.update(repo, parent.node())
+            ms = mergestatemod.mergestate.read(repo)
+            if not ms.unresolvedcount():
+                ms.reset()
+
         if origbranch != repo[b'.'].branch() and not _isbareshelve(pats, opts):
             repo.dirstate.setbranch(origbranch)