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view tests/test-pager-legacy.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 | ef6cab7930b3 |
children |
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$ cat >> fakepager.py <<EOF > import sys > for line in sys.stdin: > sys.stdout.write('paged! %r\n' % line) > EOF Enable ui.formatted because pager won't fire without it, and set up pager and tell it to use our fake pager that lets us see when the pager was running. $ cat >> $HGRCPATH <<EOF > [ui] > formatted = yes > color = no > [extensions] > pager= > [pager] > pager = "$PYTHON" $TESTTMP/fakepager.py > EOF $ hg init repo $ cd repo $ echo a >> a $ hg add a $ hg ci -m 'add a' $ for x in `"$PYTHON" $TESTDIR/seq.py 1 10`; do > echo a $x >> a > hg ci -m "modify a $x" > done By default diff and log are paged, but summary is not: $ hg diff -c 2 --pager=yes paged! 'diff -r f4be7687d414 -r bce265549556 a\n' paged! '--- a/a\tThu Jan 01 00:00:00 1970 +0000\n' paged! '+++ b/a\tThu Jan 01 00:00:00 1970 +0000\n' paged! '@@ -1,2 +1,3 @@\n' paged! ' a\n' paged! ' a 1\n' paged! '+a 2\n' $ hg log --limit 2 paged! 'changeset: 10:46106edeeb38\n' paged! 'tag: tip\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 10\n' paged! '\n' paged! 'changeset: 9:6dd8ea7dd621\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 9\n' paged! '\n' $ hg summary parent: 10:46106edeeb38 tip modify a 10 branch: default commit: (clean) update: (current) phases: 11 draft We can enable the pager on summary: $ hg --config pager.attend-summary=yes summary paged! 'parent: 10:46106edeeb38 tip\n' paged! ' modify a 10\n' paged! 'branch: default\n' paged! 'commit: (clean)\n' paged! 'update: (current)\n' paged! 'phases: 11 draft\n' $ hg --config pager.attend-diff=no diff -c 2 diff -r f4be7687d414 -r bce265549556 a --- a/a Thu Jan 01 00:00:00 1970 +0000 +++ b/a Thu Jan 01 00:00:00 1970 +0000 @@ -1,2 +1,3 @@ a a 1 +a 2 If we completely change the attend list that's respected: $ hg --config pager.attend=summary diff -c 2 diff -r f4be7687d414 -r bce265549556 a --- a/a Thu Jan 01 00:00:00 1970 +0000 +++ b/a Thu Jan 01 00:00:00 1970 +0000 @@ -1,2 +1,3 @@ a a 1 +a 2 If 'log' is in attend, then 'history' should also be paged: $ hg history --limit 2 --config pager.attend=log paged! 'changeset: 10:46106edeeb38\n' paged! 'tag: tip\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 10\n' paged! '\n' paged! 'changeset: 9:6dd8ea7dd621\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 9\n' paged! '\n' Possible bug: history is explicitly ignored in pager config, but because log is in the attend list it still gets pager treatment. $ hg history --limit 2 --config pager.attend=log \ > --config pager.ignore=history paged! 'changeset: 10:46106edeeb38\n' paged! 'tag: tip\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 10\n' paged! '\n' paged! 'changeset: 9:6dd8ea7dd621\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 9\n' paged! '\n' Possible bug: history is explicitly marked as attend-history=no, but it doesn't fail to get paged because log is still in the attend list. $ hg history --limit 2 --config pager.attend-history=no paged! 'changeset: 10:46106edeeb38\n' paged! 'tag: tip\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 10\n' paged! '\n' paged! 'changeset: 9:6dd8ea7dd621\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 9\n' paged! '\n' Possible bug: disabling pager for log but enabling it for history doesn't result in history being paged. $ hg history --limit 2 --config pager.attend-log=no \ > --config pager.attend-history=yes changeset: 10:46106edeeb38 tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: modify a 10 changeset: 9:6dd8ea7dd621 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: modify a 9 Pager should not start if stdout is not a tty. $ hg log -l1 -q --config ui.formatted=False 10:46106edeeb38 Pager with color enabled allows colors to come through by default, even though stdout is no longer a tty. $ cat >> $HGRCPATH <<EOF > [ui] > color = always > [color] > mode = ansi > EOF $ hg log --limit 3 paged! '\x1b[0;33mchangeset: 10:46106edeeb38\x1b[0m\n' paged! 'tag: tip\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 10\n' paged! '\n' paged! '\x1b[0;33mchangeset: 9:6dd8ea7dd621\x1b[0m\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 9\n' paged! '\n' paged! '\x1b[0;33mchangeset: 8:cff05a6312fe\x1b[0m\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'summary: modify a 8\n' paged! '\n' Pager works with shell aliases. $ cat >> $HGRCPATH <<EOF > [alias] > echoa = !echo a > EOF $ hg echoa a $ hg --config pager.attend-echoa=yes echoa paged! 'a\n' Pager attributes should be copied to mq repo. Otherwise pager would be started twice and color mode would be lost. $ cat >> $HGRCPATH <<EOF > [extensions] > mq = > EOF $ hg init --mq $ hg qnew foo.patch $ hg qpop popping foo.patch patch queue now empty $ hg ci --mq -m 'commit patches' $ hg log --mq --debug starting pager for command 'extension-via-attend-log' paged! '\x1b[0;33mchangeset: 0:6cc2ded15503e368aaf76b6cc3d12f320c9e3b87\x1b[0m\n' paged! 'tag: tip\n' paged! 'phase: draft\n' paged! 'parent: -1:0000000000000000000000000000000000000000\n' paged! 'parent: -1:0000000000000000000000000000000000000000\n' paged! 'manifest: 0:4980de1ae1b612014d5bcfa9507da84ce8891daa\n' paged! 'user: test\n' paged! 'date: Thu Jan 01 00:00:00 1970 +0000\n' paged! 'files+: .hgignore foo.patch series\n' paged! 'extra: branch=default\n' paged! 'description:\n' paged! 'commit patches\n' paged! '\n' paged! '\n' Pager works with hg aliases including environment variables. $ cat >> $HGRCPATH <<'EOF' > [alias] > printa = log -T "$A\n" -r 0 > EOF $ A=1 hg --config pager.attend-printa=yes printa paged! '1\n' $ A=2 hg --config pager.attend-printa=yes printa paged! '2\n' Something that's explicitly attended is still not paginated if the pager is globally set to off using a flag: $ A=2 hg --config pager.attend-printa=yes printa --pager=no 2 Pager should not override the exit code of other commands $ cat >> $TESTTMP/fortytwo.py <<'EOF' > from mercurial import commands, registrar > cmdtable = {} > command = registrar.command(cmdtable) > @command(b'fortytwo', [], b'fortytwo', norepo=True) > def fortytwo(ui, *opts): > ui.write(b'42\n') > return 42 > EOF $ cat >> $HGRCPATH <<'EOF' > [extensions] > fortytwo = $TESTTMP/fortytwo.py > EOF $ hg fortytwo --pager=on paged! '42\n' [42]