diff -r f28d5d68b71a -r a151fd01e98c mercurial/cmdutil.py
--- a/mercurial/cmdutil.py	Wed Mar 27 17:21:46 2024 +0000
+++ b/mercurial/cmdutil.py	Wed Mar 27 17:29:48 2024 +0000
@@ -4135,3 +4135,46 @@
     with repo.wlock():
         graftstate = statemod.cmdstate(repo, b'graftstate')
         return abortgraft(ui, repo, graftstate)
+
+
+def postincoming(ui, repo, modheads, optupdate, checkout, brev):
+    """Run after a changegroup has been added via pull/unbundle
+
+    This takes arguments below:
+
+    :modheads: change of heads by pull/unbundle
+    :optupdate: updating working directory is needed or not
+    :checkout: update destination revision (or None to default destination)
+    :brev: a name, which might be a bookmark to be activated after updating
+
+    return True if update raise any conflict, False otherwise.
+    """
+    if modheads == 0:
+        return False
+    if optupdate:
+        # avoid circular import
+        from . import hg
+
+        try:
+            return hg.updatetotally(ui, repo, checkout, brev)
+        except error.UpdateAbort as inst:
+            msg = _(b"not updating: %s") % stringutil.forcebytestr(inst)
+            hint = inst.hint
+            raise error.UpdateAbort(msg, hint=hint)
+    if ui.quiet:
+        pass  # we won't report anything so the other clause are useless.
+    elif modheads is not None and modheads > 1:
+        currentbranchheads = len(repo.branchheads())
+        if currentbranchheads == modheads:
+            ui.status(
+                _(b"(run 'hg heads' to see heads, 'hg merge' to merge)\n")
+            )
+        elif currentbranchheads > 1:
+            ui.status(
+                _(b"(run 'hg heads .' to see heads, 'hg merge' to merge)\n")
+            )
+        else:
+            ui.status(_(b"(run 'hg heads' to see heads)\n"))
+    elif not ui.configbool(b'commands', b'update.requiredest'):
+        ui.status(_(b"(run 'hg update' to get a working copy)\n"))
+    return False