view tests/test-basic.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

Create a repository:

#if no-extraextensions
  $ hg config
  chgserver.idletimeout=60
  devel.all-warnings=true
  devel.default-date=0 0
  extensions.fsmonitor= (fsmonitor !)
  format.use-dirstate-v2=1 (dirstate-v2 !)
  largefiles.usercache=$TESTTMP/.cache/largefiles
  lfs.usercache=$TESTTMP/.cache/lfs
  ui.slash=True
  ui.interactive=False
  ui.detailed-exit-code=True
  ui.merge=internal:merge
  ui.mergemarkers=detailed
  ui.promptecho=True
  ui.ssh=* (glob)
  ui.timeout.warn=15
  web.address=localhost
  web\.ipv6=(?:True|False) (re)
  web.server-header=testing stub value
#endif

  $ hg init t
  $ cd t

Prepare a changeset:

  $ echo a > a
  $ hg add a

  $ hg status
  A a

Writes to stdio succeed and fail appropriately

#if devfull
  $ hg status 2>/dev/full
  A a

  $ hg status >/dev/full
  abort: No space left on device* (glob)
  [255]
#endif

#if devfull
  $ hg status >/dev/full 2>&1
  [255]

  $ hg status ENOENT 2>/dev/full
  [255]
#endif

On Python 3, stdio may be None:

  $ hg debuguiprompt --config ui.interactive=true 0<&-
   abort: Bad file descriptor (no-rhg !)
   abort: response expected (rhg !)
  [255]
  $ hg version -q 0<&-
  Mercurial Distributed SCM * (glob)

#if py3 no-rhg
  $ hg version -q 1>&-
  abort: Bad file descriptor
  [255]
#else
  $ hg version -q 1>&-
#endif
  $ hg unknown -q 1>&-
  hg: unknown command 'unknown'
  (did you mean debugknown?)
  [10]

  $ hg version -q 2>&-
  Mercurial Distributed SCM * (glob)
  $ hg unknown -q 2>&-
  [10]

  $ hg commit -m test

This command is ancient:

  $ hg history
  changeset:   0:acb14030fe0a
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     test
  

Verify that updating to revision 0 via commands.update() works properly

  $ cat <<EOF > update_to_rev0.py
  > from mercurial import commands, hg, ui as uimod
  > myui = uimod.ui.load()
  > repo = hg.repository(myui, path=b'.')
  > commands.update(myui, repo, rev=b"0")
  > EOF
  $ hg up null
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ "$PYTHON" ./update_to_rev0.py
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg identify -n
  0


Poke around at hashes:

  $ hg manifest --debug
  b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 644   a

  $ hg cat a
  a

Verify should succeed:

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 1 changes to 1 files

Repository root:

  $ hg root
  $TESTTMP/t
  $ hg log -l1 -T '{reporoot}\n'
  $TESTTMP/t
  $ hg root -Tjson | sed 's|\\\\|\\|g'
  [
   {
    "hgpath": "$TESTTMP/t/.hg",
    "reporoot": "$TESTTMP/t",
    "storepath": "$TESTTMP/t/.hg/store"
   }
  ]

At the end...

  $ cd ..

Status message redirection:

  $ hg init empty

 status messages are sent to stdout by default:

  $ hg outgoing -R t empty -Tjson 2>/dev/null
  comparing with empty
  searching for changes
  [
   {
    "bookmarks": [],
    "branch": "default",
    "date": [0, 0],
    "desc": "test",
    "node": "acb14030fe0a21b60322c440ad2d20cf7685a376",
    "parents": ["0000000000000000000000000000000000000000"],
    "phase": "draft",
    "rev": 0,
    "tags": ["tip"],
    "user": "test"
   }
  ]

 which can be configured to send to stderr, so the output wouldn't be
 interleaved:

  $ cat <<'EOF' >> "$HGRCPATH"
  > [ui]
  > message-output = stderr
  > EOF
  $ hg outgoing -R t empty -Tjson 2>/dev/null
  [
   {
    "bookmarks": [],
    "branch": "default",
    "date": [0, 0],
    "desc": "test",
    "node": "acb14030fe0a21b60322c440ad2d20cf7685a376",
    "parents": ["0000000000000000000000000000000000000000"],
    "phase": "draft",
    "rev": 0,
    "tags": ["tip"],
    "user": "test"
   }
  ]
  $ hg outgoing -R t empty -Tjson >/dev/null
  comparing with empty
  searching for changes

 this option should be turned off by HGPLAIN= since it may break scripting use:

  $ HGPLAIN= hg outgoing -R t empty -Tjson 2>/dev/null
  comparing with empty
  searching for changes
  [
   {
    "bookmarks": [],
    "branch": "default",
    "date": [0, 0],
    "desc": "test",
    "node": "acb14030fe0a21b60322c440ad2d20cf7685a376",
    "parents": ["0000000000000000000000000000000000000000"],
    "phase": "draft",
    "rev": 0,
    "tags": ["tip"],
    "user": "test"
   }
  ]

 but still overridden by --config:

  $ HGPLAIN= hg outgoing -R t empty -Tjson --config ui.message-output=stderr \
  > 2>/dev/null
  [
   {
    "bookmarks": [],
    "branch": "default",
    "date": [0, 0],
    "desc": "test",
    "node": "acb14030fe0a21b60322c440ad2d20cf7685a376",
    "parents": ["0000000000000000000000000000000000000000"],
    "phase": "draft",
    "rev": 0,
    "tags": ["tip"],
    "user": "test"
   }
  ]

Invalid ui.message-output option:

  $ hg log -R t --config ui.message-output=bad
  abort: invalid ui.message-output destination: bad
  [255]

Underlying message streams should be updated when ui.fout/ferr are set:

  $ cat <<'EOF' > capui.py
  > from mercurial import pycompat, registrar
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > @command(b'capui', norepo=True)
  > def capui(ui):
  >     out = ui.fout
  >     ui.fout = pycompat.bytesio()
  >     ui.status(b'status\n')
  >     ui.ferr = pycompat.bytesio()
  >     ui.warn(b'warn\n')
  >     out.write(b'stdout: %s' % ui.fout.getvalue())
  >     out.write(b'stderr: %s' % ui.ferr.getvalue())
  > EOF
  $ hg --config extensions.capui=capui.py --config ui.message-output=stdio capui
  stdout: status
  stderr: warn