auto-upgrade: introduce a way to auto-upgrade to/from share-safe...
auto-upgrade: introduce a way to auto-upgrade to/from share-safe
This is the first "automatic-upgrade" capability. In the following commits,
similar features are coming for other "fast to upgrade" formats.
This is different from the `safe-mismatch.source-not-safe` and
`safe-mismatch.source-safe` configuration that deal with mismatch between a
share and its share-source. Here we are dealing with mismatch between a
repository configuration and its actual format.
We will need further work for cases were the repository cannot be locked. A
basic protection is in place to avoid a infinite loop for now, but it will get
proper attention in a later changeset.
Differential Revision:
https://phab.mercurial-scm.org/D12611
