hashutil: new package for hashing-related features Right now this just tries to use our sha1dc and if it's missing (eg a --pure build) we fall back to hashlib. I imagine in the future we'll want some other things in here for detecting what hasher is in use as we transition off sha1. Differential Revision: https://phab.mercurial-scm.org/D7848

sha1dc: initial implementation of Python extension A future change will use this when available to avoid sha1 collision issues until we can get moved to something else. Differential Revision: https://phab.mercurial-scm.org/D7815

sha1dc: import latest version from github After the recent SHA1 news, the attacks are serious enough we should be more proactive. This code will at least allow detection of attacks early. It's already widely deployed in Git. This is git revision 855827c583bc30645ba427885caa40c5b81764d2 of the sha1collisiondetection repo[0], with most of the files omitted. A follow-up change will introduce Python bindings for this code. 0: https://github.com/cr-marcstevens/sha1collisiondetection Differential Revision: https://phab.mercurial-scm.org/D7814

transaction: add a `hasfinalize` method The method allow code to check if an existing callback exists. It allow them to skip potentially expensive setup for a callback. Differential Revision: https://phab.mercurial-scm.org/D7832

changelog: fix the diverted opener to accept more kwargs The current code prevent the use of `atomictemp` file with the changelog opener. I do not see a good reason for this limitation. Differential Revision: https://phab.mercurial-scm.org/D7831

revlog: reorder a conditionnal about revlogio if we are using REVLOGV0, we will not use a rust based index. This small line movement make it clearer. Differential Revision: https://phab.mercurial-scm.org/D7830

rebase: delete seemingly unnecessary needupdate() This seemed to be about checking that the user hasn't updated away when we asked them to resolve merge conflicts. These days we call `cmdutil.checkunfinished()` and refuse to update, so the user shouldn't be able to get into this state. `test-rebase-interruptions.t` actually has some tests where it disables the rebase extension in order to be allowed to do some of these updates. That still passes, but I wouldn't personally haved cared if that failed. Differential Revision: https://phab.mercurial-scm.org/D7825

workingctx: move setparents() logic from localrepo to mirror overlayworkingctx It would be nice to later be able to call `wctx.setparents()` whether `wctx` is a `workingctx` or an `overlayworkingctx`. Differential Revision: https://phab.mercurial-scm.org/D7823

overlayworkginctx: implement a setparents() to mirror dirstate.setparents() This lets us make the in-memory and on-disk code a bit more similar. I'll soon also implement setparents() on the regular workingctx. Differential Revision: https://phab.mercurial-scm.org/D7822

overlayworkingctx: default branch to base context's branch This matches what the dirstate does (it reuses working copy parent's branch unless told otherwise). By moving the default out of `rebase.commitmemorynode()`, it will let us clean that up better later. Differential Revision: https://phab.mercurial-scm.org/D7821