Mercurial > hg
view tests/test-exchange-obsmarkers-case-A5.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 | 34a46d48d24e |
children |
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============================================ Testing obsolescence markers push: Cases A.5 ============================================ Mercurial pushes obsolescences markers relevant to the "pushed-set", the set of all changesets that requested to be "in sync" after the push (even if they are already on both side). This test belongs to a series of tests checking such set is properly computed and applied. This does not tests "obsmarkers" discovery capabilities. Category A: simple cases TestCase 5: partial reordering A.5 partial reordering ====================== .. .. {{{ .. B ø⇠⇠ .. | ⇡ .. A ø⇠⇠⇠○ A' .. | ⇡/ .. | ○ B' .. |/ .. ● O .. }}} .. .. Marker exist from: .. .. * `Aø⇠○ A'` .. * `Bø⇠○ B'` .. .. Command run: .. .. * hg push -r B .. .. Expected exchange: .. .. * `Bø⇠○ B'` .. .. Expected Exclude: .. .. * `Aø⇠○ A'` Setup ----- $ . $TESTDIR/testlib/exchange-obsmarker-util.sh initial $ setuprepos A.5 creating test repo for test case A.5 - pulldest - main - pushdest cd into `main` and proceed with env setup $ cd main $ mkcommit A0 $ mkcommit B0 $ hg update 0 0 files updated, 0 files merged, 2 files removed, 0 files unresolved $ mkcommit B1 created new head $ mkcommit A1 $ hg debugobsolete aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa `getid 'desc(A0)'` 1 new obsolescence markers $ hg debugobsolete `getid 'desc(B0)'` `getid 'desc(B1)'` 1 new obsolescence markers obsoleted 1 changesets $ hg debugobsolete `getid 'desc(A0)'` `getid 'desc(A1)'` 1 new obsolescence markers obsoleted 1 changesets $ hg log -G --hidden @ 8c0a98c83722 (draft): A1 | o f6298a8ac3a4 (draft): B1 | | x 6e72f0a95b5e (draft): B0 | | | x 28b51eb45704 (draft): A0 |/ o a9bdc8b26820 (public): O $ inspect_obsmarkers obsstore content ================ aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} 6e72f0a95b5e01a7504743aa941f69cb1fbef8b0 f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 8c0a98c8372212c6efde4bfdcef006f27ff759d3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} $ cd .. $ cd .. Actual Test ----------- $ dotest A.5 B1 ## Running testcase A.5 # testing echange of "B1" (f6298a8ac3a4) ## initial state # obstore: main 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 8c0a98c8372212c6efde4bfdcef006f27ff759d3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} 6e72f0a95b5e01a7504743aa941f69cb1fbef8b0 f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pushdest # obstore: pulldest ## pushing "B1" from main to pushdest pushing to pushdest searching for changes remote: adding changesets remote: adding manifests remote: adding file changes remote: added 1 changesets with 1 changes to 1 files remote: 1 new obsolescence markers ## post push state # obstore: main 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 8c0a98c8372212c6efde4bfdcef006f27ff759d3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} 6e72f0a95b5e01a7504743aa941f69cb1fbef8b0 f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pushdest 6e72f0a95b5e01a7504743aa941f69cb1fbef8b0 f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pulldest ## pulling "f6298a8ac3a4" from main into pulldest pulling from main searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files 1 new obsolescence markers new changesets f6298a8ac3a4 (1 drafts) (run 'hg update' to get a working copy) ## post pull state # obstore: main 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 8c0a98c8372212c6efde4bfdcef006f27ff759d3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} 6e72f0a95b5e01a7504743aa941f69cb1fbef8b0 f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 28b51eb45704506b5c603decd6bf7ac5e0f6a52f 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pushdest 6e72f0a95b5e01a7504743aa941f69cb1fbef8b0 f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pulldest 6e72f0a95b5e01a7504743aa941f69cb1fbef8b0 f6298a8ac3a4b78bbeae5f1d3dc5bc3c3812f0f3 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}