bundle: exit early when there are no commits to bundle Previously, if you passed a revset that resolved to no nodes, it would get interpreted by the changegroup discovery logic as 'bundle all my heads', which is not what the user asked. Let's exit early when we notice this case. It could be argued that the changeset discovery logic should be smarter and only assume 'all heads' if the incoming heads parameter is None, but that's a much riskier change.

zeroconf: access repo on hgweb_mod properly (issue5036) hgweb_mod.hgweb.repo disappeared in ae33fff17c1e (hg: establish a cache for localrepository instances) and the code for accessing repo instances from hgweb was later refactored to go through a cache-aware context manager. Adapt zeroconf to access the repo instance via the new API.