Mercurial > hg
view tests/test-convert-hg-source.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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$ cat >> $HGRCPATH <<EOF > [extensions] > convert= > [convert] > hg.saverev=False > EOF $ hg init orig $ cd orig $ echo foo > foo $ echo bar > bar $ hg ci -qAm 'add foo bar' -d '0 0' $ echo >> foo $ hg ci -m 'change foo' -d '1 0' $ hg up -qC 0 $ hg copy --after --force foo bar $ hg copy foo baz $ hg ci -m 'make bar and baz copies of foo' -d '2 0' created new head Test that template can print all file copies (issue4362) $ hg log -r . --template "{file_copies % ' File: {file_copy}\n'}" File: bar (foo) File: baz (foo) $ hg bookmark premerge1 $ hg merge -r 1 merging baz and foo to baz 1 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -m 'merge local copy' -d '3 0' $ hg up -C 1 1 files updated, 0 files merged, 1 files removed, 0 files unresolved (leaving bookmark premerge1) $ hg bookmark premerge2 $ hg merge 2 merging foo and baz to baz 1 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -m 'merge remote copy' -d '4 0' created new head Make and delete some tags $ hg tag that $ hg tag --remove that $ hg tag this #if execbit $ chmod +x baz #else $ echo some other change to make sure we get a rev 5 > baz #endif $ hg ci -m 'mark baz executable' -d '5 0' $ cd .. $ hg convert --datesort orig new 2>&1 | grep -v 'subversion python bindings could not be loaded' initializing destination new repository scanning source... sorting... converting... 8 add foo bar 7 change foo 6 make bar and baz copies of foo 5 merge local copy 4 merge remote copy 3 Added tag that for changeset 8601262d7472 2 Removed tag that 1 Added tag this for changeset 706614b458c1 0 mark baz executable updating bookmarks $ cd new $ hg out ../orig comparing with ../orig searching for changes no changes found [1] #if execbit $ hg bookmarks premerge1 3:973ef48a98a4 premerge2 8:c4968fdf2e5d #else Different hash because no x bit $ hg bookmarks premerge1 3:973ef48a98a4 premerge2 8:1cc21e701444 #endif Test that redoing a convert results in an identical graph $ cd ../ $ rm new/.hg/shamap $ hg convert --datesort orig new 2>&1 | grep -v 'subversion python bindings could not be loaded' scanning source... sorting... converting... 8 add foo bar 7 change foo 6 make bar and baz copies of foo 5 merge local copy 4 merge remote copy 3 Added tag that for changeset 8601262d7472 2 Removed tag that 1 Added tag this for changeset 706614b458c1 0 mark baz executable updating bookmarks $ hg -R new log -G -T '{rev} {desc}' o 8 mark baz executable | o 7 Added tag this for changeset 706614b458c1 | o 6 Removed tag that | o 5 Added tag that for changeset 8601262d7472 | o 4 merge remote copy |\ +---o 3 merge local copy | |/ | o 2 make bar and baz copies of foo | | o | 1 change foo |/ o 0 add foo bar check shamap LF and CRLF handling $ cat > rewrite.py <<EOF > import sys > # Interlace LF and CRLF > lines = [(l.rstrip() + ((i % 2) and b'\n' or b'\r\n')) > for i, l in enumerate(open(sys.argv[1], 'rb'))] > open(sys.argv[1], 'wb').write(b''.join(lines)) > EOF $ "$PYTHON" rewrite.py new/.hg/shamap $ cd orig $ hg up -qC 1 $ echo foo >> foo $ hg ci -qm 'change foo again' $ hg up -qC 2 $ echo foo >> foo $ hg ci -qm 'change foo again again' $ cd .. $ hg convert --datesort orig new 2>&1 | grep -v 'subversion python bindings could not be loaded' scanning source... sorting... converting... 1 change foo again again 0 change foo again updating bookmarks init broken repository $ hg init broken $ cd broken $ echo a >> a $ echo b >> b $ hg ci -qAm init $ echo a >> a $ echo b >> b $ hg copy b c $ hg ci -qAm changeall $ hg up -qC 0 $ echo bc >> b $ hg ci -m changebagain created new head $ HGMERGE=internal:local hg -q merge $ hg ci -m merge $ hg mv b d $ hg ci -m moveb break it #if reporevlogstore $ rm .hg/store/data/b.* #endif #if reposimplestore $ rm .hg/store/data/b/* #endif $ cd .. $ hg --config convert.hg.ignoreerrors=True convert broken fixed initializing destination fixed repository scanning source... sorting... converting... 4 init ignoring: data/b@1e88685f5ddec574a34c70af492f95b6debc8741: no match found (reporevlogstore !) ignoring: data/b/index@1e88685f5dde: no node (reposimplestore !) 3 changeall 2 changebagain 1 merge 0 moveb $ hg -R fixed verify checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 5 changesets with 5 changes to 3 files manifest -r 0 $ hg -R fixed manifest -r 0 a manifest -r tip $ hg -R fixed manifest -r tip a c d $ cd .. $ hg init commit-references $ cd commit-references $ echo a > a $ hg ci -Aqm initial $ echo b > b $ hg ci -Aqm 'the previous commit was 1451231c8757' $ echo c > c $ hg ci -Aqm 'the working copy is called ffffffffffff' $ cd .. $ hg convert commit-references new-commit-references -q \ > --config convert.hg.sourcename=yes $ cd new-commit-references $ hg log -T '{node|short} {desc}\n' fe295c9e6bc6 the working copy is called ffffffffffff 642508659503 the previous commit was c2491f685436 c2491f685436 initial