# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@octobus.net>
# Date 1709906814 -3600
# Node ID 0ddc34330d4147c99f0d6aa1d87ddac8fa166c15
# Parent  2b5f4013f79f29f6a12d432d37a95c4d9a395745
branchcache: do not accept "empty update"

This currently does not happens and it will be simpler that is remains that way.
If all update do something, we will be able to simply declare, in a later
changesets, that all update to result in a dirty branchcache.

diff -r 2b5f4013f79f -r 0ddc34330d41 mercurial/branchmap.py
--- a/mercurial/branchmap.py	Thu Mar 07 11:04:34 2024 +0100
+++ b/mercurial/branchmap.py	Fri Mar 08 15:06:54 2024 +0100
@@ -302,7 +302,8 @@
                 self._closednodes.add(cl.node(r))
             max_rev = max(max_rev, r)
         if max_rev < 0:
-            max_rev = None
+            msg = "running branchcache.update without revision to update"
+            raise error.ProgrammingError(msg)
 
         # Delay fetching the topological heads until they are needed.
         # A repository without non-continous branches can skip this part.