$ hg init repo

  $ cd repo

  $ echo a > a

  $ hg add a

  $ hg commit -m test

Do we ever miss a sub-second change?:

  $ for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20; do

  >     hg co -qC 0

  >     echo b > a

  >     hg st

  > done

  M a

  M a

  M a

  M a

  M a

  M a

  M a

  M a

  M a

  M a

  M a

  M a

  M a

  M a

  M a

  M a

  M a

  M a

  M a

  M a

  $ echo test > b

  $ mkdir dir1

  $ echo test > dir1/c

  $ echo test > d

  $ echo test > e

#if execbit

A directory will typically have the execute bit -- make sure it doesn't get

confused with a file with the exec bit set

  $ chmod +x e

#endif

  $ hg add b dir1 d e

  adding dir1/c (glob)

  $ hg commit -m test2

  $ cat >> $TESTTMP/dirstaterace.py << EOF

  > from mercurial import (

  >     context,

  >     extensions,

  > )

  > def extsetup():

  >     extensions.wrapfunction(context.workingctx, '_checklookup', overridechecklookup)

  > def overridechecklookup(orig, self, files):

  >     # make an update that changes the dirstate from underneath

  >     self._repo.ui.system(r"sh '$TESTTMP/dirstaterace.sh'",

  >                          cwd=self._repo.root)

  >     return orig(self, files)

  > EOF

  $ hg debugrebuilddirstate

  $ hg debugdirstate

  n   0         -1 unset               a

  n   0         -1 unset               b

  n   0         -1 unset               d

  n   0         -1 unset               dir1/c

  n   0         -1 unset               e

XXX Note that this returns M for files that got replaced by directories. This is

definitely a bug, but the fix for that is hard and the next status run is fine

anyway.

  $ cat > $TESTTMP/dirstaterace.sh <<EOF

  > rm b && rm -r dir1 && rm d && mkdir d && rm e && mkdir e

  > EOF

  $ hg status --config extensions.dirstaterace=$TESTTMP/dirstaterace.py

  M d

  M e

  ! b

  ! dir1/c

  $ hg debugdirstate

  n 644          2 * a (glob)

  n   0         -1 unset               b

  n   0         -1 unset               d

  n   0         -1 unset               dir1/c

  n   0         -1 unset               e

  $ hg status

  ! b

  ! d

  ! dir1/c

  ! e

  $ rmdir d e

  $ hg update -C -q .

Test that dirstate changes aren't written out at the end of "hg

status", if .hg/dirstate is already changed simultaneously before

acquisition of wlock in workingctx._poststatusfixup().

This avoidance is important to keep consistency of dirstate in race

condition (see issue5584 for detail).

  $ hg parents -q

  1:* (glob)

  $ hg debugrebuilddirstate

  $ hg debugdirstate

  n   0         -1 unset               a

  n   0         -1 unset               b

  n   0         -1 unset               d

  n   0         -1 unset               dir1/c

  n   0         -1 unset               e

  $ cat > $TESTTMP/dirstaterace.sh <<EOF

  > # This script assumes timetable of typical issue5584 case below:

  > #

  > # 1. "hg status" loads .hg/dirstate

  > # 2. "hg status" confirms clean-ness of FILE

  > # 3. "hg update -C 0" updates the working directory simultaneously

  > #    (FILE is removed, and FILE is dropped from .hg/dirstate)

  > # 4. "hg status" acquires wlock

  > #    (.hg/dirstate is re-loaded = no FILE entry in dirstate)

  > # 5. "hg status" marks FILE in dirstate as clean

  > #    (FILE entry is added to in-memory dirstate)

  > # 6. "hg status" writes dirstate changes into .hg/dirstate

  > #    (FILE entry is written into .hg/dirstate)

  > #

  > # To reproduce similar situation easily and certainly, #2 and #3

  > # are swapped.  "hg cat" below ensures #2 on "hg status" side.

  > 

  > hg update -q -C 0

  > hg cat -r 1 b > b

  > EOF

"hg status" below should excludes "e", of which exec flag is set, for

portability of test scenario, because unsure but missing "e" is

treated differently in _checklookup() according to runtime platform.

- "missing(!)" on POSIX, "pctx[f].cmp(self[f])" raises ENOENT

- "modified(M)" on Windows, "self.flags(f) != pctx.flags(f)" is True

  $ hg status --config extensions.dirstaterace=$TESTTMP/dirstaterace.py --debug -X path:e

  skip updating dirstate: identity mismatch

  M a

  ! d

  ! dir1/c

  $ hg parents -q

  0:* (glob)

  $ hg files

  a

  $ hg debugdirstate

  n * * * a (glob)