rollback: show that the safety works in a associated test That test section is checking that --force is overcoming the safety check, however we did not check that the safety properly detect the situation. We now do for clarity.

dirstate-guard: remove its usage in `backout` We can simply replace it with a transaction.

dirstate-guard: remove the usage in `import` It is now redundant with the transaction spawning the same scope.

dirstate-guard: replace a usage in `rebase` with a transaction Opening the transaction sooner will provide us with the same benefit.

dirstate-guard: remove usage in `rebase` Now that the dirstate change and write are clearer, it does not seems we need to use a dirstate-guard here anymore. The transaction already wrap the full operation.

dirstate-guard: remove it usage in `mq` The code it covered is also covered by a `changing_parents` context.

dirstate: enforce the use of `changing_files` context to change tracking Now that everything is using the new context, we can start enforcing its usage.

dirstate: warn if we write to the dirstate without holding the wlock Writing the dirstate without holding the wlock can race with other update and overwrite important change. The comment questionning the current state of things was right, we should the `wlock` should always cover the dirstate. (Yes, this is me, agreeing with myself, half a decade later).

dirstate: avoid transaction backup/restore if we do not hold the lock Doing overwriting the dirstate content without holding the lock is a recipe for disaster.

dirstate: issue a developer warning on implicit write on wlock release Our goal is to get rid of all these to clarify the writing pattern, so it is time to warn about this (and later, forbid it).