.arcconfig

revlog: make sure we never use sparserevlog without general delta (issue6056)

We are getting user report where the delta code tries to use `sparse-revlog`
logic on repository where `generaldelta` is disabled. This can't work so we
ensure the two booleans have a consistent value.

Creating this kind of repository is not expected to be possible the current bug
report point at a clonebundle related bug that is still to be properly isolated
(Yuya Nishihara seems to a have done it).

Corrupting a repository to reproduce the issue is possible. A test using this
method is included in this fix.

{
    "conduit_uri": "https://phab.mercurial-scm.org/api",
    "repository.callsign": "HG",
    "arc.land.onto.default": "@",
    "base": "hg:.^"
}