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
#require serve
$ hg init test
$ cd test
$ echo foo>foo
$ hg addremove
adding foo
$ hg commit -m 1
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files
$ hg serve -p $HGPORT -d --pid-file=hg.pid
$ cat hg.pid >> $DAEMON_PIDS
$ cd ..
$ hg clone --pull http://foo:bar@localhost:$HGPORT/ copy
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 340e38bdcde4
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd copy
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files
$ hg co
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat foo
foo
$ hg manifest --debug
2ed2a3912a0b24502043eae84ee4b279c18b90dd 644 foo
$ hg pull
pulling from http://foo@localhost:$HGPORT/
searching for changes
no changes found
$ hg rollback --dry-run --verbose
repository tip rolled back to revision -1 (undo pull: http://foo:***@localhost:$HGPORT/)
Test pull of non-existing 20 character revision specification, making sure plain ascii identifiers
not are encoded like a node:
$ hg pull -r 'xxxxxxxxxxxxxxxxxxxy'
pulling from http://foo@localhost:$HGPORT/
abort: unknown revision 'xxxxxxxxxxxxxxxxxxxy'
[255]
$ hg pull -r 'xxxxxxxxxxxxxxxxxx y'
pulling from http://foo@localhost:$HGPORT/
abort: unknown revision 'xxxxxxxxxxxxxxxxxx y'
[255]
Test pull of working copy revision
$ hg pull -r 'ffffffffffff'
pulling from http://foo@localhost:$HGPORT/
abort: unknown revision 'ffffffffffff'
[255]
Test 'file:' uri handling:
$ hg pull -q file://../test-does-not-exist
abort: file:// URLs can only refer to localhost
[255]
$ hg pull -q file://../test
abort: file:// URLs can only refer to localhost
[255]
MSYS changes 'file:' into 'file;'
#if no-msys
$ hg pull -q file:../test # no-msys
#endif
It's tricky to make file:// URLs working on every platform with
regular shell commands.
$ URL=`"$PYTHON" -c "from __future__ import print_function; import os; print('file://foobar' + ('/' + os.getcwd().replace(os.sep, '/')).replace('//', '/') + '/../test')"`
$ hg pull -q "$URL"
abort: file:// URLs can only refer to localhost
[255]
$ URL=`"$PYTHON" -c "from __future__ import print_function; import os; print('file://localhost' + ('/' + os.getcwd().replace(os.sep, '/')).replace('//', '/') + '/../test')"`
$ hg pull -q "$URL"
SEC: check for unsafe ssh url
$ cat >> $HGRCPATH << EOF
> [ui]
> ssh = sh -c "read l; read l; read l"
> EOF
$ hg pull 'ssh://-oProxyCommand=touch${IFS}owned/path'
pulling from ssh://-oProxyCommand%3Dtouch%24%7BIFS%7Downed/path
abort: potentially unsafe url: 'ssh://-oProxyCommand=touch${IFS}owned/path'
[255]
$ hg pull 'ssh://%2DoProxyCommand=touch${IFS}owned/path'
pulling from ssh://-oProxyCommand%3Dtouch%24%7BIFS%7Downed/path
abort: potentially unsafe url: 'ssh://-oProxyCommand=touch${IFS}owned/path'
[255]
$ hg pull 'ssh://fakehost|touch${IFS}owned/path'
pulling from ssh://fakehost%7Ctouch%24%7BIFS%7Downed/path
abort: no suitable response from remote hg
[255]
$ hg --config ui.timestamp-output=true pull 'ssh://fakehost%7Ctouch%20owned/path'
\[20[2-9][0-9]-[01][0-9]-[0-3][0-9]T[0-5][0-9]:[0-5][0-9]:[0-5][0-9]\.[0-9][0-9][0-9][0-9][0-9][0-9]\] pulling from ssh://fakehost%7Ctouch%20owned/path (re)
\[20[2-9][0-9]-[01][0-9]-[0-3][0-9]T[0-5][0-9]:[0-5][0-9]:[0-5][0-9]\.[0-9][0-9][0-9][0-9][0-9][0-9]\] abort: no suitable response from remote hg (re)
[255]
$ [ ! -f owned ] || echo 'you got owned'
$ cd ..