Mercurial > hg
view tests/test-identify.t @ 49000:dd6b67d5c256 stable
rust: fix unsound `OwningDirstateMap`
As per the previous patch, `OwningDirstateMap` is unsound. Self-referential
structs are difficult to implement correctly in Rust since the compiler is
free to move structs around as much as it wants to. They are also very rarely
needed in practice, so the state-of-the-art on how they should be done within
the Rust rules is still a bit new.
The crate `ouroboros` is an attempt at providing a safe way (in the Rust sense)
of declaring self-referential structs. It is getting a lot attention and was
improved very quickly when soundness issues were found in the past: rather than
relying on our own (limited) review circle, we might as well use the de-facto
common crate to fix this problem. This will give us a much better chance of
finding issues should any new ones be discovered as well as the benefit of
fewer `unsafe` APIs of our own.
I was starting to think about how I would present a safe API to the old struct
but soon realized that the callback-based approach was already done in
`ouroboros`, along with a lot more care towards refusing incorrect structs.
In short: we don't return a mutable reference to the `DirstateMap` anymore, we
expect users of its API to pass a `FnOnce` that takes the map as an argument.
This allows our `OwningDirstateMap` to control the input and output lifetimes
of the code that modifies it to prevent such issues.
Changing to `ouroboros` meant changing every API with it, but it is relatively
low churn in the end. It correctly identified the example buggy modification of
`copy_map_insert` outlined in the previous patch as violating the borrow rules.
Differential Revision: https://phab.mercurial-scm.org/D12429
author | Raphaël Gomès <rgomes@octobus.net> |
---|---|
date | Tue, 05 Apr 2022 10:55:28 +0200 |
parents | 95c4cca641f6 |
children |
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#require serve #if no-outer-repo no repo $ hg id abort: there is no Mercurial repository here (.hg not found) [10] #endif create repo $ hg init test $ cd test $ echo a > a $ hg ci -Ama adding a basic id usage $ hg id cb9a9f314b8b tip $ hg id --debug cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b tip $ hg id -q cb9a9f314b8b $ hg id -v cb9a9f314b8b tip with options $ hg id -r. cb9a9f314b8b tip $ hg id -n 0 $ hg id -t tip $ hg id -b default $ hg id -i cb9a9f314b8b $ hg id -n -t -b -i cb9a9f314b8b 0 default tip $ hg id -Tjson [ { "bookmarks": [], "branch": "default", "dirty": "", "id": "cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b", "node": "ffffffffffffffffffffffffffffffffffffffff", "parents": ["cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b"], "tags": ["tip"] } ] test template keywords and functions which require changectx: $ hg id -T '{rev} {node|shortest}\n' 2147483647 ffff $ hg id -T '{parents % "{rev} {node|shortest} {desc}\n"}' 0 cb9a a $ hg id -T '{parents}\n' cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b test nested template: '{tags}'/'{node}' constants shouldn't override the default keywords, but '{id}' persists because there's no default keyword for '{id}' (issue5612) $ hg id -T '{tags}\n' tip $ hg id -T '{revset("null:.") % "{rev}:{node|short} {tags} {id|short}\n"}' -1:000000000000 cb9a9f314b8b 0:cb9a9f314b8b tip cb9a9f314b8b with modifications $ echo b > a $ hg id -n -t -b -i cb9a9f314b8b+ 0+ default tip $ hg id -Tjson [ { "bookmarks": [], "branch": "default", "dirty": "+", "id": "cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b+", "node": "ffffffffffffffffffffffffffffffffffffffff", "parents": ["cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b"], "tags": ["tip"] } ] other local repo $ cd .. $ hg -R test id cb9a9f314b8b+ tip #if no-outer-repo $ hg id test cb9a9f314b8b+ tip #endif with remote http repo $ cd test $ hg serve -p $HGPORT1 -d --pid-file=hg.pid $ cat hg.pid >> $DAEMON_PIDS $ hg id http://localhost:$HGPORT1/ cb9a9f314b8b remote with rev number? $ hg id -n http://localhost:$HGPORT1/ abort: can't query remote revision number, branch, or tags [10] remote with tags? $ hg id -t http://localhost:$HGPORT1/ abort: can't query remote revision number, branch, or tags [10] remote with branch? $ hg id -b http://localhost:$HGPORT1/ abort: can't query remote revision number, branch, or tags [10] test bookmark support $ hg bookmark Y $ hg bookmark Z $ hg bookmarks Y 0:cb9a9f314b8b * Z 0:cb9a9f314b8b $ hg id cb9a9f314b8b+ tip Y/Z $ hg id --bookmarks Y Z test remote identify with bookmarks $ hg id http://localhost:$HGPORT1/ cb9a9f314b8b Y/Z $ hg id --bookmarks http://localhost:$HGPORT1/ Y Z $ hg id -r . http://localhost:$HGPORT1/ cb9a9f314b8b Y/Z $ hg id --bookmarks -r . http://localhost:$HGPORT1/ Y Z test invalid lookup $ hg id -r noNoNO http://localhost:$HGPORT1/ abort: unknown revision 'noNoNO' [255] Make sure we do not obscure unknown requires file entries (issue2649) $ echo fake >> .hg/requires $ hg id abort: repository requires features unknown to this Mercurial: fake (see https://mercurial-scm.org/wiki/MissingRequirement for more information) [255] $ cd .. #if no-outer-repo $ hg id test abort: repository requires features unknown to this Mercurial: fake (see https://mercurial-scm.org/wiki/MissingRequirement for more information) [255] #endif