view tests/test-context.py @ 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

from __future__ import absolute_import, print_function
import os
import stat
import sys
from mercurial.node import hex
from mercurial import (
    context,
    diffutil,
    encoding,
    hg,
    scmutil,
    ui as uimod,
)

print_ = print


def print(*args, **kwargs):
    """print() wrapper that flushes stdout buffers to avoid py3 buffer issues

    We could also just write directly to sys.stdout.buffer the way the
    ui object will, but this was easier for porting the test.
    """
    print_(*args, **kwargs)
    sys.stdout.flush()


def printb(data, end=b'\n'):
    out = getattr(sys.stdout, 'buffer', sys.stdout)
    out.write(data + end)
    out.flush()


ui = uimod.ui.load()

repo = hg.repository(ui, b'test1', create=1)
os.chdir('test1')

# create 'foo' with fixed time stamp
f = open('foo', 'wb')
f.write(b'foo\n')
f.close()
os.utime('foo', (1000, 1000))

# add+commit 'foo'
repo[None].add([b'foo'])
repo.commit(text=b'commit1', date=b"0 0")

d = repo[None][b'foo'].date()
if os.name == 'nt':
    d = d[:2]
print("workingfilectx.date = (%d, %d)" % d)

# test memctx with non-ASCII commit message


def filectxfn(repo, memctx, path):
    return context.memfilectx(repo, memctx, b"foo", b"")


ctx = context.memctx(
    repo,
    [b'tip', None],
    encoding.tolocal(b"Gr\xc3\xbcezi!"),
    [b"foo"],
    filectxfn,
)
ctx.commit()
for enc in "ASCII", "Latin-1", "UTF-8":
    encoding.encoding = enc
    printb(b"%-8s: %s" % (enc.encode('ascii'), repo[b"tip"].description()))

# test performing a status


def getfilectx(repo, memctx, f):
    fctx = memctx.p1()[f]
    data, flags = fctx.data(), fctx.flags()
    if f == b'foo':
        data += b'bar\n'
    return context.memfilectx(
        repo, memctx, f, data, b'l' in flags, b'x' in flags
    )


ctxa = repo[0]
ctxb = context.memctx(
    repo,
    [ctxa.node(), None],
    b"test diff",
    [b"foo"],
    getfilectx,
    ctxa.user(),
    ctxa.date(),
)

print(ctxb.status(ctxa))

# test performing a diff on a memctx
diffopts = diffutil.diffallopts(repo.ui, {b'git': True})
for d in ctxb.diff(ctxa, opts=diffopts):
    printb(d, end=b'')

# test safeness and correctness of "ctx.status()"
print('= checking context.status():')

# ancestor "wcctx ~ 2"
actx2 = repo[b'.']

repo.wwrite(b'bar-m', b'bar-m\n', b'')
repo.wwrite(b'bar-r', b'bar-r\n', b'')
repo[None].add([b'bar-m', b'bar-r'])
repo.commit(text=b'add bar-m, bar-r', date=b"0 0")

# ancestor "wcctx ~ 1"
actx1 = repo[b'.']

repo.wwrite(b'bar-m', b'bar-m bar-m\n', b'')
repo.wwrite(b'bar-a', b'bar-a\n', b'')
repo[None].add([b'bar-a'])
repo[None].forget([b'bar-r'])

# status at this point:
#   M bar-m
#   A bar-a
#   R bar-r
#   C foo

from mercurial import scmutil

print('== checking workingctx.status:')

wctx = repo[None]
print('wctx._status=%s' % (str(wctx._status)))

print('=== with "pattern match":')
print(
    actx1.status(other=wctx, match=scmutil.matchfiles(repo, [b'bar-m', b'foo']))
)
print('wctx._status=%s' % (str(wctx._status)))
print(
    actx2.status(other=wctx, match=scmutil.matchfiles(repo, [b'bar-m', b'foo']))
)
print('wctx._status=%s' % (str(wctx._status)))

print('=== with "always match" and "listclean=True":')
print(actx1.status(other=wctx, listclean=True))
print('wctx._status=%s' % (str(wctx._status)))
print(actx2.status(other=wctx, listclean=True))
print('wctx._status=%s' % (str(wctx._status)))

print("== checking workingcommitctx.status:")

wcctx = context.workingcommitctx(
    repo,
    scmutil.status([b'bar-m'], [b'bar-a'], [], [], [], [], []),
    text=b'',
    date=b'0 0',
)
print('wcctx._status=%s' % (str(wcctx._status)))

print('=== with "always match":')
print(actx1.status(other=wcctx))
print('wcctx._status=%s' % (str(wcctx._status)))
print(actx2.status(other=wcctx))
print('wcctx._status=%s' % (str(wcctx._status)))

print('=== with "always match" and "listclean=True":')
print(actx1.status(other=wcctx, listclean=True))
print('wcctx._status=%s' % (str(wcctx._status)))
print(actx2.status(other=wcctx, listclean=True))
print('wcctx._status=%s' % (str(wcctx._status)))

print('=== with "pattern match":')
print(
    actx1.status(
        other=wcctx, match=scmutil.matchfiles(repo, [b'bar-m', b'foo'])
    )
)
print('wcctx._status=%s' % (str(wcctx._status)))
print(
    actx2.status(
        other=wcctx, match=scmutil.matchfiles(repo, [b'bar-m', b'foo'])
    )
)
print('wcctx._status=%s' % (str(wcctx._status)))

print('=== with "pattern match" and "listclean=True":')
print(
    actx1.status(
        other=wcctx,
        match=scmutil.matchfiles(repo, [b'bar-r', b'foo']),
        listclean=True,
    )
)
print('wcctx._status=%s' % (str(wcctx._status)))
print(
    actx2.status(
        other=wcctx,
        match=scmutil.matchfiles(repo, [b'bar-r', b'foo']),
        listclean=True,
    )
)
print('wcctx._status=%s' % (str(wcctx._status)))

os.chdir('..')

# test manifestlog being changed
print('== commit with manifestlog invalidated')

repo = hg.repository(ui, b'test2', create=1)
os.chdir('test2')

# make some commits
for i in [b'1', b'2', b'3']:
    with open(i, 'wb') as f:
        f.write(i)
    status = scmutil.status([], [i], [], [], [], [], [])
    ctx = context.workingcommitctx(
        repo, status, text=i, user=b'[e-mail]', date=(0, 0)
    )
    ctx.p1().manifest()  # side effect: cache manifestctx
    n = repo.commitctx(ctx)
    printb(b'commit %s: %s' % (i, hex(n)))

    # touch 00manifest.i mtime so storecache could expire.
    # repo.__dict__['manifestlog'] is deleted by transaction releasefn.
    st = repo.svfs.stat(b'00manifest.i')
    repo.svfs.utime(
        b'00manifest.i', (st[stat.ST_MTIME] + 1, st[stat.ST_MTIME] + 1)
    )

    # read the file just committed
    try:
        if repo[n][i].data() != i:
            print('data mismatch')
    except Exception as ex:
        print('cannot read data: %r' % ex)

with repo.wlock(), repo.lock(), repo.transaction(b'test'):
    with open(b'4', 'wb') as f:
        f.write(b'4')
    repo.dirstate.set_tracked(b'4')
    repo.commit(b'4')
    revsbefore = len(repo.changelog)
    repo.invalidate(clearfilecache=True)
    revsafter = len(repo.changelog)
    if revsbefore != revsafter:
        print('changeset lost by repo.invalidate()')