resolve: suggest the next action

Expose afterresolvedstates to allow graft and similar to
suggest a message when resolving results in no unresolved
files.

If there isn't a matching state in afterresolvedstates,
then if verbose, suggest commiting.

mercurial/cmdutil.py

@@ -3363,6 +3363,17 b' def clearunfinished(repo):'
         if clearable and repo.vfs.exists(f):
             util.unlink(repo.join(f))
 
+afterresolvedstates = [
+    ]
+
+def checkafterresolved(repo):
+    contmsg = _("continue: %s\n")
+    for f, msg in afterresolvedstates:
+        if repo.vfs.exists(f):
+            repo.ui.warn(contmsg % msg)
+            return
+    repo.ui.note(contmsg % _("hg commit"))
+
 class dirstateguard(object):
     '''Restore dirstate at unexpected failure.
 

mercurial/commands.py

@@ -6003,6 +6003,7 b' def resolve(ui, repo, *pats, **opts):'
     driverresolvedf = list(ms.driverresolved())
     if not unresolvedf and not driverresolvedf:
         ui.status(_('(no more unresolved files)\n'))
+        cmdutil.checkafterresolved(repo)
     elif not unresolvedf:
         ui.status(_('(no more unresolved files -- '
                     'run "hg resolve --all" to conclude)\n'))

tests/test-backout.t

@@ -714,6 +714,7 b' Test usage of `hg resolve` in case of co'
   my foo@b71750c4b0fd+ other foo@a30dd8addae3 ancestor foo@913609522437
    premerge successful
   (no more unresolved files)
+  continue: hg commit
   $ hg status
   M foo
   ? foo.orig