packaging: split Inno installer building from Mercurial building We want to make the logic for producing the installer agnostic about how Mercurial is built to allow for alternate build methods (like PyOxidizer). Differential Revision: https://phab.mercurial-scm.org/D8472

packaging: remove pyoxidizer.bzl from packaging directory We have another version in rust/hgcli that is more modern and is already associated with our Rust CLI project. Differential Revision: https://phab.mercurial-scm.org/D8471

contrib: install PyOxidizer in Linux and Windows environments For Linux, this was trivial. For Windows, we need to teach the powershell script to install Rust as well. This was also pretty straightforward. Differential Revision: https://phab.mercurial-scm.org/D8468

diff: re-establish linear runtime performance The previous method with sum() and list() creates a new list object for every hunk. Then sum() is used to flatten out this sequence of lists. The sum() function is not "lazy", but creates a new list object for every "+" operation and so this code had quadratic runtime behaviour.

copies: fix the changeset based algorithm regarding merge In 99ebde4fec99, we changed the list of files stored into the `files` field. This lead to the changeset centric copy algorithm to break in various merge situation involving merge. Older information could reach the merge through `p1`, and while information from `p2` was strictly fresher, it would get overwritten anyway. We update the situation with more details about which revision introduces rename information. This help use making the right decision in case of merge. We are now running a more comprehensive suite of test with include this kind of situation. The behavior differ slightly from the filelog based in a couple of instance. There is mostly two distinct cases: 1) there are conflicting rename information in a merge (different rename history on each side). In this case the filelog based implementation arbitrarily pick a side based on the file-revision-number. So it depends on a local factor. The changeset centric algorithm will use a deterministic approach, by picking the information coming from the first parent of the merge. This is stable across different clone. 2) rename information related to file that exist in both source and destination. The filelog based implementation do not even try to detect these, however the changeset centric one get them for "free" (it is simpler to detect them than not). The new implementation focus on correctness. Performance improvement will come later. Differential Revision: https://phab.mercurial-scm.org/D8244

merge with stable

rust-chg: clean up excessive indents Differential Revision: https://phab.mercurial-scm.org/D8450

rust-chg: do not terminate tokio runtime until pager exits We no longer need to spawn a task just to keep the pager handle. The pager handle can be held by ChgUiHandler since the handler itself is not consumed and recreated across async calls. Differential Revision: https://phab.mercurial-scm.org/D8449

rust-chg: modernize entry function Finally the entire build passes. There's a bug that run() no longer waits for the spawned pager, which will be fixed by the next patch. Differential Revision: https://phab.mercurial-scm.org/D8448

rust-chg: reimplement locator by using async/await and tokio-0.2 connect_spawned() is rewritten from scratch by using std::process. Before, it would select completion of either connection or server process. New code could be implemented as such, but it's much simpler to occasionally run try_wait() to detect server death. Differential Revision: https://phab.mercurial-scm.org/D8447