lfs: add a method to the local blobstore to convert OIDs to file paths This is less ugly than passing an open callback to the `httpsendfile` constuctor. Differential Revision: https://phab.mercurial-scm.org/D7961

merge: introduce a revert_to() for that use-case In the same vein as the previous patch. Differential Revision: https://phab.mercurial-scm.org/D7901

merge: introduce a clean_update() for that use-case I find it hard to understand what value to pass for all the arguments to `merge.update()`. I would like to introduce functions that are more specific to each use-case. We already have `graft()`. This patch introduces a `clean_update()` and uses it in some places to show that it works. Differential Revision: https://phab.mercurial-scm.org/D7902

manifest: fix _very_ subtle bug with exact matchers passed to walk() Prior to this fix, manifestdict.walk() with an exact matcher would blindly list the files in the matcher, even if they weren't in the manifest. This was exposed by my next patch where I rewrite filesnotin() to use walk() instead of matches(). Differential Revision: https://phab.mercurial-scm.org/D8081

rust-utils: add `Escaped` trait This will be used as a general interface for displaying things to the user. The upcoming `IncludeMatcher` will use it to store its patterns in a user-displayable string. Differential Revision: https://phab.mercurial-scm.org/D7870

rust-dirs-multiset: add `DirsChildrenMultiset` In a future patch, this structure will be needed to store information needed by the (also upcoming) `IgnoreMatcher`. Differential Revision: https://phab.mercurial-scm.org/D7869