Mercurial > hg
view tests/test-narrow-exchange.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 | 96ee8ca99f5a |
children | 92892dff03f3 |
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#testcases lfs-on lfs-off #if lfs-on $ cat >> $HGRCPATH <<EOF > [extensions] > lfs = > EOF #endif $ . "$TESTDIR/narrow-library.sh" create full repo $ hg init master $ cd master $ cat >> .hg/hgrc <<EOF > [narrow] > serveellipses=True > EOF $ mkdir inside $ echo 1 > inside/f $ mkdir inside2 $ echo 1 > inside2/f $ mkdir outside $ echo 1 > outside/f $ hg ci -Aqm 'initial' $ echo 2 > inside/f $ hg ci -qm 'inside 2' $ echo 2 > inside2/f $ hg ci -qm 'inside2 2' $ echo 2 > outside/f $ hg ci -qm 'outside 2' $ cd .. $ hg clone --narrow ssh://user@dummy/master narrow --include inside requesting all changes adding changesets adding manifests adding file changes added 3 changesets with 2 changes to 1 files new changesets *:* (glob) updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg clone --narrow ssh://user@dummy/master narrow2 --include inside --include inside2 requesting all changes adding changesets adding manifests adding file changes added 4 changesets with 4 changes to 2 files new changesets *:* (glob) updating to branch default 2 files updated, 0 files merged, 0 files removed, 0 files unresolved Can push to wider repo if change does not affect paths in wider repo that are not also in narrower repo $ cd narrow $ echo 3 > inside/f $ hg ci -m 'inside 3' $ hg push ssh://user@dummy/narrow2 pushing to ssh://user@dummy/narrow2 searching for changes remote: adding changesets remote: adding manifests remote: adding file changes remote: added 1 changesets with 1 changes to 1 files Can push to narrower repo if change affects only paths within remote's narrow spec $ cd ../narrow2 $ cat >> .hg/hgrc <<EOF > [narrow] > serveellipses=True > EOF $ hg co -r 'desc("inside 3")' 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo 4 > inside/f $ hg ci -m 'inside 4' $ hg push ssh://user@dummy/narrow pushing to ssh://user@dummy/narrow searching for changes remote: adding changesets remote: adding manifests remote: adding file changes remote: added 1 changesets with 1 changes to 1 files Can push to narrow repo if change affects only paths outside remote's narrow spec $ echo 3 > inside2/f $ hg ci -m 'inside2 3' TODO: this should be successful $ hg push ssh://user@dummy/narrow pushing to ssh://user@dummy/narrow searching for changes remote: adding changesets remote: adding manifests remote: adding file changes remote: transaction abort! remote: rollback completed remote: abort: data/inside2/f@4a1aa07735e673e20c00fae80f40dc301ee30616: unknown parent (reporevlogstore !) remote: abort: data/inside2/f/index@4a1aa07735e6: no node (reposimplestore !) abort: stream ended unexpectedly (got 0 bytes, expected 4) [255] Can pull from wider repo if change affects only paths outside remote's narrow spec $ echo 4 > inside2/f $ hg ci -m 'inside2 4' $ hg log -G -T '{rev} {node|short} {files}\n' @ 7 d78a96df731d inside2/f | o 6 8c26f5218962 inside2/f | o 5 ba3480e2f9de inside/f | o 4 4e5edd526618 inside/f | o 3 81e7e07b7ab0 outside/f | o 2 f3993b8c0c2b inside2/f | o 1 8cd66ca966b4 inside/f | o 0 c8057d6f53ab inside/f inside2/f outside/f $ cd ../narrow $ hg log -G -T '{rev} {node|short} {files}\n' o 4 ba3480e2f9de inside/f | @ 3 4e5edd526618 inside/f | o 2 81e7e07b7ab0 outside/f | o 1 8cd66ca966b4 inside/f | o 0 c8057d6f53ab inside/f inside2/f outside/f $ hg pull ssh://user@dummy/narrow2 pulling from ssh://user@dummy/narrow2 searching for changes adding changesets adding manifests adding file changes added 1 changesets with 0 changes to 0 files new changesets d78a96df731d (run 'hg update' to get a working copy) Check that the resulting history is valid in the full repo $ cd ../narrow2 $ hg push ssh://user@dummy/master pushing to ssh://user@dummy/master searching for changes remote: adding changesets remote: adding manifests remote: adding file changes remote: added 4 changesets with 4 changes to 2 files $ cd ../master $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 8 changesets with 10 changes to 3 files Can not push to wider repo if change affects paths in wider repo that are not also in narrower repo $ cd ../master $ hg co -r 'desc("inside2 4")' 2 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo 5 > inside2/f $ hg ci -m 'inside2 5' $ hg log -G -T '{rev} {node|short} {files}\n' @ 8 5970befb64ba inside2/f | o 7 d78a96df731d inside2/f | o 6 8c26f5218962 inside2/f | o 5 ba3480e2f9de inside/f | o 4 4e5edd526618 inside/f | o 3 81e7e07b7ab0 outside/f | o 2 f3993b8c0c2b inside2/f | o 1 8cd66ca966b4 inside/f | o 0 c8057d6f53ab inside/f inside2/f outside/f $ cd ../narrow $ hg pull pulling from ssh://user@dummy/master searching for changes adding changesets adding manifests adding file changes added 1 changesets with 0 changes to 0 files new changesets * (glob) (run 'hg update' to get a working copy) TODO: this should tell the user that their narrow clone does not have the necessary content to be able to push to the target TODO: lfs shouldn't abort like this $ hg push ssh://user@dummy/narrow2 || true pushing to ssh://user@dummy/narrow2 searching for changes remote: adding changesets remote: adding manifests remote: adding file changes remote: added 1 changesets with 0 changes to 0 files (no-lfs-on !) remote: error: pretxnchangegroup.lfs hook raised an exception: data/inside2/f@f59b4e0218355383d2789196f1092abcf2262b0c: no match found (lfs-on !) remote: transaction abort! (lfs-on !) remote: rollback completed (lfs-on !) remote: abort: data/inside2/f@f59b4e0218355383d2789196f1092abcf2262b0c: no match found (lfs-on !) abort: stream ended unexpectedly (got 0 bytes, expected 4) (lfs-on !)