diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -2466,7 +2466,7 @@
                 ui.status(
                     _(b'working directory now based on revision %d\n') % parents
                 )
-            mergestatemod.mergestate.clean(self, self[b'.'].node())
+            self[None].mergestate(clean=True)
 
         # TODO: if we know which new heads may result from this rollback, pass
         # them to destroy(), which will prevent the branchhead cache from being
@@ -2865,7 +2865,7 @@
                 fparent2 = nullid
             elif not fparentancestors:
                 # TODO: this whole if-else might be simplified much more
-                ms = mergestatemod.mergestate.read(self)
+                ms = self[None].mergestate()
                 if (
                     fname in ms
                     and ms[fname] == mergestatemod.MERGE_RECORD_MERGED_OTHER
@@ -2966,7 +2966,7 @@
                 self, status, text, user, date, extra
             )
 
-            ms = mergestatemod.mergestate.read(self)
+            ms = self[None].mergestate()
             mergeutil.checkunresolved(ms)
 
             # internal config: ui.allowemptycommit