rewind: compatibility with cmdutil.revert() without parents argument

hgext3rd/evolve/rewind.py

@@ -151,4 +151,7 @@
                     revertopts = {'no_backup': True, 'all': True,
                                   'rev': oldctx.node()}
                     with ui.configoverride({(b'ui', b'quiet'): True}):
+                        code = cmdutil.revert.__code__
+                        # hg <= 5.5 (8c466bcb0879)
+                        if r'parents' in code.co_varnames[:code.co_argcount]:
                             cmdutil.revert(repo.ui, repo, oldctx,
@@ -154,5 +157,8 @@
                             cmdutil.revert(repo.ui, repo, oldctx,
-                                       repo.dirstate.parents(), **revertopts)
+                                           repo.dirstate.parents(),
+                                           **revertopts)
+                        else:
+                            cmdutil.revert(repo.ui, repo, oldctx, **revertopts)
                 else:
                     hg.updaterepo(repo, update_target, False)