diff --git a/mercurial/state.py b/mercurial/state.py
--- a/mercurial/state.py
+++ b/mercurial/state.py
@@ -16,6 +16,8 @@
 
 from __future__ import absolute_import
 
+import contextlib
+
 from .i18n import _
 
 from . import error, pycompat, util
@@ -114,6 +116,7 @@
         reportonly,
         continueflag,
         stopflag,
+        childopnames,
         cmdmsg,
         cmdhint,
         statushint,
@@ -127,6 +130,7 @@
         self._reportonly = reportonly
         self._continueflag = continueflag
         self._stopflag = stopflag
+        self._childopnames = childopnames
         self._cmdmsg = cmdmsg
         self._cmdhint = cmdhint
         self._statushint = statushint
@@ -185,6 +189,7 @@
 
 # A list of statecheck objects for multistep operations like graft.
 _unfinishedstates = []
+_unfinishedstatesbyname = {}
 
 
 def addunfinished(
@@ -195,6 +200,7 @@
     reportonly=False,
     continueflag=False,
     stopflag=False,
+    childopnames=[],
     cmdmsg=b'',
     cmdhint=b'',
     statushint=b'',
@@ -217,6 +223,8 @@
     `--continue` option or not.
     stopflag is a boolean that determines whether or not a command supports
     --stop flag
+    childopnames is a list of other opnames this op uses as sub-steps of its
+    own execution. They must already be added.
     cmdmsg is used to pass a different status message in case standard
     message of the format "abort: cmdname in progress" is not desired.
     cmdhint is used to pass a different hint message in case standard
@@ -237,17 +245,69 @@
         reportonly,
         continueflag,
         stopflag,
+        childopnames,
         cmdmsg,
         cmdhint,
         statushint,
         abortfunc,
         continuefunc,
     )
+
     if opname == b'merge':
         _unfinishedstates.append(statecheckobj)
     else:
+        # This check enforces that for any op 'foo' which depends on op 'bar',
+        # 'foo' comes before 'bar' in _unfinishedstates. This ensures that
+        # getrepostate() always returns the most specific applicable answer.
+        for childopname in childopnames:
+            if childopname not in _unfinishedstatesbyname:
+                raise error.ProgrammingError(
+                    _(b'op %s depends on unknown op %s') % (opname, childopname)
+                )
+
         _unfinishedstates.insert(0, statecheckobj)
 
+    if opname in _unfinishedstatesbyname:
+        raise error.ProgrammingError(_(b'op %s registered twice') % opname)
+    _unfinishedstatesbyname[opname] = statecheckobj
+
+
+@contextlib.contextmanager
+def delegating(repo, opname, childopname):
+    """context wrapper for delegations from opname to childopname.
+
+    requires that childopname was specified when opname was registered.
+
+    Usage:
+      def my_command_foo_that_uses_rebase(...):
+        ...
+        with state.delegating(repo, 'foo', 'rebase'):
+          _run_rebase(...)
+        ...
+    """
+
+    s = _unfinishedstatesbyname[parentopname]
+    if not s:
+        raise error.ProgrammingError(_(b'unknown op %s') % opname)
+    if childopname not in s._childopnames:
+        raise error.ProgrammingError(
+            _(b'op %s does not delegate to %s') % (opname, childopname)
+        )
+    c = _unfinishedstatesbyname[childopname]
+
+    newskipstates = set(repo.ui.configlist(b'commands', b'status.skipstates'))
+    newskipstates.add(childopname)
+    with repo.ui.configoverride(
+        {(b'commands', b'status.skipstates'): newskipstates}
+    ):
+        try:
+            yield
+        except error.ConflictResolutionRequired as e:
+            # Rewrite conflict resolution advice for the parent opname.
+            if e.opname == childopname:
+                raise error.ConflictResolutionRequired(opname)
+            raise e
+
 
 addunfinished(
     b'update',