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
$ . "$TESTDIR/histedit-helpers.sh"
$ cat >> $HGRCPATH <<EOF
> [extensions]
> histedit=
> strip=
> mockmakedate = $TESTDIR/mockmakedate.py
> EOF
$ initrepo ()
> {
> hg init r
> cd r
> for x in a b c d e f g; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> }
$ initrepo
log before edit
$ hg log --graph
@ changeset: 6:3c6a8ed2ebe8
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: g
|
o changeset: 5:652413bf663e
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 4:e860deea161a
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 3:055a42cdd887
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 2:177f92b77385
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
dirty a file
$ echo a > g
$ hg histedit 177f92b77385 --commands - 2>&1 << EOF
> EOF
abort: uncommitted changes
[20]
$ echo g > g
edit the history
$ hg histedit 177f92b77385 --commands - 2>&1 << EOF| fixbundle
> pick 177f92b77385 c
> pick 055a42cdd887 d
> edit e860deea161a e
> pick 652413bf663e f
> pick 3c6a8ed2ebe8 g
> EOF
0 files updated, 0 files merged, 3 files removed, 0 files unresolved
Editing (e860deea161a), commit as needed now to split the change
(to edit e860deea161a, `hg histedit --continue` after making changes)
try to update and get an error
$ hg update tip
abort: histedit in progress
(use 'hg histedit --continue' or 'hg histedit --abort')
[20]
edit the plan via the editor
$ cat >> $TESTTMP/editplan.sh <<EOF
> cat > \$1 <<EOF2
> drop e860deea161a e
> drop 652413bf663e f
> drop 3c6a8ed2ebe8 g
> EOF2
> EOF
$ HGEDITOR="sh $TESTTMP/editplan.sh" hg histedit --edit-plan
$ cat .hg/histedit-state
v1
055a42cdd88768532f9cf79daa407fc8d138de9b
3c6a8ed2ebe862cc949d2caa30775dd6f16fb799
False
3
drop
e860deea161a2f77de56603b340ebbb4536308ae
drop
652413bf663ef2a641cab26574e46d5f5a64a55a
drop
3c6a8ed2ebe862cc949d2caa30775dd6f16fb799
0
strip-backup/177f92b77385-0ebe6a8f-histedit.hg
edit the plan via --commands
$ hg histedit --edit-plan --commands - 2>&1 << EOF
> edit e860deea161a e
> pick 652413bf663e f
> drop 3c6a8ed2ebe8 g
> EOF
$ cat .hg/histedit-state
v1
055a42cdd88768532f9cf79daa407fc8d138de9b
3c6a8ed2ebe862cc949d2caa30775dd6f16fb799
False
3
edit
e860deea161a2f77de56603b340ebbb4536308ae
pick
652413bf663ef2a641cab26574e46d5f5a64a55a
drop
3c6a8ed2ebe862cc949d2caa30775dd6f16fb799
0
strip-backup/177f92b77385-0ebe6a8f-histedit.hg
Go at a random point and try to continue
$ hg id -n
3+
$ hg up 0
abort: histedit in progress
(use 'hg histedit --continue' or 'hg histedit --abort')
[20]
Try to delete necessary commit
$ hg strip -r 652413b
abort: histedit in progress, can't strip 652413bf663e
[255]
commit, then edit the revision
$ hg ci -m 'wat'
created new head
$ echo a > e
qnew should fail while we're in the middle of the edit step
$ hg --config extensions.mq= qnew please-fail
abort: histedit in progress
(use 'hg histedit --continue' or 'hg histedit --abort')
[20]
$ HGEDITOR='echo foobaz > ' hg histedit --continue 2>&1 | fixbundle
$ hg log --graph
@ changeset: 6:b5f70786f9b0
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 5:a5e1ba2f7afb
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: foobaz
|
o changeset: 4:1a60820cd1f6
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: wat
|
o changeset: 3:055a42cdd887
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 2:177f92b77385
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
$ hg cat e
a
Stripping necessary commits should not break --abort
$ hg histedit 1a60820cd1f6 --commands - 2>&1 << EOF| fixbundle
> edit 1a60820cd1f6 wat
> pick a5e1ba2f7afb foobaz
> pick b5f70786f9b0 g
> EOF
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
Editing (1a60820cd1f6), commit as needed now to split the change
(to edit 1a60820cd1f6, `hg histedit --continue` after making changes)
$ mv .hg/histedit-state .hg/histedit-state.bak
$ hg strip -q -r b5f70786f9b0
$ mv .hg/histedit-state.bak .hg/histedit-state
$ hg histedit --abort
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 3 files
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg log -r .
changeset: 6:b5f70786f9b0
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: f
check histedit_source
$ hg log --debug --rev 5
changeset: 5:a5e1ba2f7afb899ef1581cea528fd885d2fca70d
phase: draft
parent: 4:1a60820cd1f6004a362aa622ebc47d59bc48eb34
parent: -1:0000000000000000000000000000000000000000
manifest: 5:5ad3be8791f39117565557781f5464363b918a45
user: test
date: Thu Jan 01 00:00:00 1970 +0000
files: e
extra: branch=default
extra: histedit_source=e860deea161a2f77de56603b340ebbb4536308ae
description:
foobaz
$ hg histedit tip --commands - 2>&1 <<EOF| fixbundle
> edit b5f70786f9b0 f
> EOF
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
Editing (b5f70786f9b0), commit as needed now to split the change
(to edit b5f70786f9b0, `hg histedit --continue` after making changes)
$ hg status
A f
$ hg summary
parent: 5:a5e1ba2f7afb
foobaz
branch: default
commit: 1 added (new branch head)
update: 1 new changesets (update)
phases: 7 draft
hist: 1 remaining (histedit --continue)
(test also that editor is invoked if histedit is continued for
"edit" action)
$ HGEDITOR='cat' hg histedit --continue
f
HG: Enter commit message. Lines beginning with 'HG:' are removed.
HG: Leave message empty to abort commit.
HG: --
HG: user: test
HG: branch 'default'
HG: added f
saved backup bundle to $TESTTMP/r/.hg/strip-backup/b5f70786f9b0-c28d9c86-histedit.hg
$ hg status
log after edit
$ hg log --limit 1
changeset: 6:a107ee126658
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: f
say we'll change the message, but don't.
$ cat > ../edit.sh <<EOF
> cat "\$1" | sed s/pick/mess/ > tmp
> mv tmp "\$1"
> EOF
$ HGEDITOR="sh ../edit.sh" hg histedit tip 2>&1 | fixbundle
$ hg status
$ hg log --limit 1
changeset: 6:1fd3b2fe7754
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: f
modify the message
check saving last-message.txt, at first
$ cat > $TESTTMP/commitfailure.py <<EOF
> from mercurial import error
> def reposetup(ui, repo):
> class commitfailure(repo.__class__):
> def commit(self, *args, **kwargs):
> raise error.Abort(b'emulating unexpected abort')
> repo.__class__ = commitfailure
> EOF
$ cat >> .hg/hgrc <<EOF
> [extensions]
> # this failure occurs before editor invocation
> commitfailure = $TESTTMP/commitfailure.py
> EOF
$ cat > $TESTTMP/editor.sh <<EOF
> echo "==== before editing"
> cat \$1
> echo "===="
> echo "check saving last-message.txt" >> \$1
> EOF
(test that editor is not invoked before transaction starting)
$ rm -f .hg/last-message.txt
$ HGEDITOR="sh $TESTTMP/editor.sh" hg histedit tip --commands - 2>&1 << EOF | fixbundle
> mess 1fd3b2fe7754 f
> EOF
abort: emulating unexpected abort
$ test -f .hg/last-message.txt
[1]
$ cat >> .hg/hgrc <<EOF
> [extensions]
> commitfailure = !
> EOF
$ hg histedit --abort -q
(test that editor is invoked and commit message is saved into
"last-message.txt")
$ cat >> .hg/hgrc <<EOF
> [hooks]
> # this failure occurs after editor invocation
> pretxncommit.unexpectedabort = false
> EOF
$ hg status --rev '1fd3b2fe7754^1' --rev 1fd3b2fe7754
A f
$ rm -f .hg/last-message.txt
$ HGEDITOR="sh $TESTTMP/editor.sh" hg histedit tip --commands - 2>&1 << EOF
> mess 1fd3b2fe7754 f
> EOF
==== before editing
f
HG: Enter commit message. Lines beginning with 'HG:' are removed.
HG: Leave message empty to abort commit.
HG: --
HG: user: test
HG: branch 'default'
HG: added f
====
transaction abort!
rollback completed
note: commit message saved in .hg/last-message.txt
note: use 'hg commit --logfile .hg/last-message.txt --edit' to reuse it
abort: pretxncommit.unexpectedabort hook exited with status 1
[40]
$ cat .hg/last-message.txt
f
check saving last-message.txt
(test also that editor is invoked if histedit is continued for "message"
action)
$ HGEDITOR=cat hg histedit --continue
f
HG: Enter commit message. Lines beginning with 'HG:' are removed.
HG: Leave message empty to abort commit.
HG: --
HG: user: test
HG: branch 'default'
HG: added f
transaction abort!
rollback completed
note: commit message saved in .hg/last-message.txt
note: use 'hg commit --logfile .hg/last-message.txt --edit' to reuse it
abort: pretxncommit.unexpectedabort hook exited with status 1
[40]
$ cat >> .hg/hgrc <<EOF
> [hooks]
> pretxncommit.unexpectedabort =
> EOF
$ hg histedit --abort -q
then, check "modify the message" itself
$ hg histedit tip --commands - 2>&1 << EOF | fixbundle
> mess 1fd3b2fe7754 f
> EOF
$ hg status
$ hg log --limit 1
changeset: 6:62feedb1200e
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: f
rollback should not work after a histedit
$ hg rollback
no rollback information available
[1]
$ cd ..
$ hg clone -qr0 r r0
$ cd r0
$ hg phase -fdr0
$ hg histedit --commands - 0 2>&1 << EOF
> edit cb9a9f314b8b a > $EDITED
> EOF
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
Editing (cb9a9f314b8b), commit as needed now to split the change
(to edit cb9a9f314b8b, `hg histedit --continue` after making changes)
[240]
$ HGEDITOR=true hg histedit --continue
saved backup bundle to $TESTTMP/r0/.hg/strip-backup/cb9a9f314b8b-cc5ccb0b-histedit.hg
$ hg log -G
@ changeset: 0:0efcea34f18a
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
$ echo foo >> b
$ hg addr
adding b
$ hg ci -m 'add b'
$ echo foo >> a
$ hg ci -m 'extend a'
$ hg phase --public 1
Attempting to fold a change into a public change should not work:
$ cat > ../edit.sh <<EOF
> cat "\$1" | sed s/pick/fold/ > tmp
> mv tmp "\$1"
> EOF
$ HGEDITOR="sh ../edit.sh" hg histedit 2
warning: histedit rules saved to: .hg/histedit-last-edit.txt
hg: parse error: first changeset cannot use verb "fold"
[10]
$ cat .hg/histedit-last-edit.txt
fold 0012be4a27ea 2 extend a
# Edit history between 0012be4a27ea and 0012be4a27ea
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but allow edits before making new commit
# m, mess = edit commit message without changing commit content
# p, fold = use commit
# b, base = checkout changeset and apply further changesets from there
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
$ cd ..
============================================
Test update-timestamp config option in mess|
============================================
$ addwithdate ()
> {
> echo $1 > $1
> hg add $1
> hg ci -m $1 -d "$2 0"
> }
$ initrepo ()
> {
> hg init r2
> cd r2
> addwithdate a 1
> addwithdate b 2
> addwithdate c 3
> addwithdate d 4
> addwithdate e 5
> addwithdate f 6
> }
$ initrepo
log before edit
$ hg log --limit 1
changeset: 5:178e35e0ce73
tag: tip
user: test
date: Thu Jan 01 00:00:06 1970 +0000
summary: f
$ hg histedit tip --commands - 2>&1 --config rewrite.update-timestamp=True << EOF | fixbundle
> mess 178e35e0ce73 f
> EOF
log after edit
$ hg log --limit 1
changeset: 5:98bf456d476b
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: f
$ cd ..
warn the user on editing tagged commits
$ hg init issue4017
$ cd issue4017
$ echo > a
$ hg ci -Am 'add a'
adding a
$ hg tag a
$ hg tags
tip 1:bd7ee4f3939b
a 0:a8a82d372bb3
$ hg histedit
warning: tags associated with the given changeset will be lost after histedit.
do you want to continue (yN)? n
abort: histedit cancelled
[250]
$ cd ..