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view tests/test-amend-subrepo.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 | 4b7d5d10c45d |
children | c84844cd523a |
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#testcases obsstore-off obsstore-on $ cat << EOF >> $HGRCPATH > [extensions] > amend = > EOF #if obsstore-on $ cat << EOF >> $HGRCPATH > [experimental] > evolution.createmarkers = True > EOF #endif Prepare parent repo ------------------- $ hg init r $ cd r $ echo a > a $ hg ci -Am0 adding a Link first subrepo ------------------ $ echo 's = s' >> .hgsub $ hg add .hgsub $ hg init s amend without .hgsub $ hg amend s abort: can't commit subrepos without .hgsub [255] amend with subrepo $ hg amend saved backup bundle to * (glob) (obsstore-off !) $ hg status --change . A .hgsub A .hgsubstate A a $ cat .hgsubstate 0000000000000000000000000000000000000000 s Update subrepo -------------- add new commit to be amended $ echo a >> a $ hg ci -m1 amend with dirty subrepo $ echo a >> s/a $ hg add -R s adding s/a $ hg amend abort: uncommitted changes in subrepository "s" (use --subrepos for recursive commit) [255] amend with modified subrepo $ hg ci -R s -m0 $ hg amend saved backup bundle to * (glob) (obsstore-off !) $ hg status --change . M .hgsubstate M a $ cat .hgsubstate f7b1eb17ad24730a1651fccd46c43826d1bbc2ac s revert subrepo change $ hg up -R s -q null $ hg amend saved backup bundle to * (glob) (obsstore-off !) $ hg status --change . M a Link another subrepo -------------------- add new commit to be amended $ echo b >> b $ hg ci -qAm2 also checks if non-subrepo change is included $ echo a >> a amend with another subrepo $ hg init t $ echo b >> t/b $ hg ci -R t -Am0 adding b $ echo 't = t' >> .hgsub $ hg amend saved backup bundle to * (glob) (obsstore-off !) $ hg status --change . M .hgsub M .hgsubstate M a A b $ cat .hgsubstate 0000000000000000000000000000000000000000 s bfb1a4fb358498a9533dabf4f2043d94162f1fcd t Unlink one subrepo ------------------ add new commit to be amended $ echo a >> a $ hg ci -m3 $ echo 't = t' > .hgsub --interactive won't silently ignore dirty subrepos $ echo modified > t/b $ hg amend --interactive --config ui.interactive=True abort: uncommitted changes in subrepository "t" [255] $ hg amend --interactive --config ui.interactive=True --config ui.commitsubrepos=True abort: uncommitted changes in subrepository "t" [255] $ hg -R t revert -q --all --no-backup amend with one subrepo dropped $ hg amend saved backup bundle to * (glob) (obsstore-off !) $ hg status --change . M .hgsub M .hgsubstate M a $ cat .hgsubstate bfb1a4fb358498a9533dabf4f2043d94162f1fcd t Unlink subrepos completely -------------------------- add new commit to be amended $ echo a >> a $ hg ci -m3 amend with .hgsub removed $ hg rm .hgsub $ hg amend saved backup bundle to * (glob) (obsstore-off !) $ hg status --change . M a R .hgsub R .hgsubstate broken repositories will refuse to push #if obsstore-off $ hg up -q -C 2 #else $ hg up -q -C 6 #endif $ echo c >> t/b $ hg amend -q -R t $ hg init ../dest $ hg init ../dest/t $ hg init ../dest/s $ hg push -q ../dest abort: subrepo 't' is hidden in revision 04aa62396ec6 (obsstore-on !) abort: subrepo 't' not found in revision 04aa62396ec6 (obsstore-off !) [255] ... unless forced $ hg push --force -q ../dest $ hg verify -R ../dest checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 5 changesets with 12 changes to 4 files checking subrepo links subrepo 't' not found in revision 04aa62396ec6 subrepo 't' not found in revision 6bce99600681 $ cd ..