Mercurial > hg
view tests/test-repair-strip.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 | 7a4e1d245f19 |
children | c84844cd523a |
line wrap: on
line source
#require unix-permissions no-root reporevlogstore $ cat > $TESTTMP/dumpjournal.py <<EOF > import sys > for entry in sys.stdin.read().split('\n'): > if entry: > print(entry.split('\x00')[0]) > EOF $ echo "[extensions]" >> $HGRCPATH $ echo "mq=">> $HGRCPATH $ teststrip() { > hg -q up -C $1 > echo % before update $1, strip $2 > hg parents > chmod -$3 $4 > hg strip $2 2>&1 | sed 's/\(bundle\).*/\1/' | sed 's/Permission denied.*\.hg\/store\/\(.*\)/Permission denied \.hg\/store\/\1/' > echo % after update $1, strip $2 > chmod +$3 $4 > hg verify > echo % journal contents > if [ -f .hg/store/journal ]; then > cat .hg/store/journal | "$PYTHON" $TESTTMP/dumpjournal.py > else > echo "(no journal)" > fi > if ls .hg/store/journal >/dev/null 2>&1; then > hg recover --verify > fi > ls .hg/strip-backup/* >/dev/null 2>&1 && hg unbundle -q .hg/strip-backup/* > rm -rf .hg/strip-backup > } $ hg init test $ cd test $ echo a > a $ hg -q ci -m "a" -A $ echo b > b $ hg -q ci -m "b" -A $ echo b2 >> b $ hg -q ci -m "b2" -A $ echo c > c $ hg -q ci -m "c" -A $ teststrip 0 2 w .hg/store/data/b.i % before update 0, strip 2 changeset: 0:cb9a9f314b8b user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: a saved backup bundle transaction abort! failed to truncate data/b.i rollback failed - please run hg recover (failure reason: [Errno *] Permission denied .hg/store/data/b.i') (glob) strip failed, backup bundle abort: Permission denied .hg/store/data/b.i' % after update 0, strip 2 abandoned transaction found - run hg recover checking changesets checking manifests crosschecking files in changesets and manifests checking files b@?: rev 1 points to nonexistent changeset 2 (expected 1) b@?: 736c29771fba not in manifests warning: orphan data file 'data/c.i' checked 2 changesets with 3 changes to 2 files 2 warnings encountered! 2 integrity errors encountered! % journal contents 00changelog.i 00manifest.i data/b.i data/c.i rolling back interrupted transaction checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 2 changesets with 2 changes to 2 files $ teststrip 0 2 r .hg/store/data/b.i % before update 0, strip 2 changeset: 0:cb9a9f314b8b user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: a abort: Permission denied .hg/store/data/b.i' % after update 0, strip 2 checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 4 changesets with 4 changes to 3 files % journal contents (no journal) $ teststrip 0 2 w .hg/store/00manifest.i % before update 0, strip 2 changeset: 0:cb9a9f314b8b user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: a saved backup bundle transaction abort! failed to truncate 00manifest.i rollback failed - please run hg recover (failure reason: [Errno *] Permission denied .hg/store/00manifest.i') (glob) strip failed, backup bundle abort: Permission denied .hg/store/00manifest.i' % after update 0, strip 2 abandoned transaction found - run hg recover checking changesets checking manifests manifest@?: rev 2 points to nonexistent changeset 2 manifest@?: 3362547cdf64 not in changesets manifest@?: rev 3 points to nonexistent changeset 3 manifest@?: 265a85892ecb not in changesets crosschecking files in changesets and manifests c@3: in manifest but not in changeset checking files b@?: rev 1 points to nonexistent changeset 2 (expected 1) c@?: rev 0 points to nonexistent changeset 3 checked 2 changesets with 4 changes to 3 files 1 warnings encountered! 7 integrity errors encountered! (first damaged changeset appears to be 3) % journal contents 00changelog.i 00manifest.i data/b.i data/c.i rolling back interrupted transaction checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 2 changesets with 2 changes to 2 files $ cd ..