copies: rename some function to the new naming scheme We are about to introduce more function and more variants, it seems better to align everything on the new scheme, allowing `_` for clarify. We do this aligned in a dedicated changeset to make the next changesets simpler. Differential Revision: https://phab.mercurial-scm.org/D9113

changing-files: cache the various property We are going to start using them more having some basic caching would be good. The focus is not about performance yet, however avoid some easy N² trap seems reasonable. Differential Revision: https://phab.mercurial-scm.org/D9112

changing-files: always use `mark_touched` to update the touched set We use this function internally too because that will make cache invalidation simpler. Differential Revision: https://phab.mercurial-scm.org/D9111

changing-files: fix docstring As pointed by Pulkit Goyal. Differential Revision: https://phab.mercurial-scm.org/D9143

rust: move rustfmt.toml to repo root so it can be used by `hg fix` `hg fix` runs the formatters from the repo root so it doesn't pick up the `rustfmt.toml` configs we had in each the `hg-core`, `hg-cpython`, and `rhg` packages, which resulted in warnings about `async fn` not existing in Rust 2015. This patch moves the `rustfmt.toml` file to the root so `hg fix` will use it. By putting the `rustfmt.toml` file in a higher-level directory, it also applies to the `chg` and `hgcli` packages. That makes `test-check-rust-format.t` fail, so this patch also applies the new formatting rules to those packages. Differential Revision: https://phab.mercurial-scm.org/D9142

merge: if CHANGED_DELETED and KEEP_NEW are actions, choose CHANGED_DELETED ACTION_KEEP_NEW and ACTION_CHANGED_DELETED are conflicting actions as one says that file is new while other says that file was present earlier and has changed-delete conflicts. Let's do changed-delete which will lead to conflicts and make user choose the right way.

tests: fix a typo in `desc()` revset in test-merge-criss-cross.t I was looking into fixing the broken behavior only to find out that we had a typo in the commit message and merge was not performed.

merge: if DELETED_CHANGED and GET are in actions, choose DELETED_CHANGED ACTION_GET represents that either the file is created on remote or it's newer on the remote side. However, since we have a ACTION_DELETE_CHANGED too, it means the file is not present locally and ACTION_GET is representing that file was created on remote. Having both ACTION_GET and ACTION_DELETED_CHANGED is conflicting because one says that file was created on remote and other says file has delete-changed conflicts. Let's choose ACTION_DELETED_CHANGED which will result in conflicts and make user choose the right way forward.

tests: add newfilenode test case in test-merge-changedelete.t

rust: leverage improved match ergonomics Differential Revision: https://phab.mercurial-scm.org/D9137