view tests/test-dirstate-race2.t @ 44399:a45ffad9ae98

merge: introduce a merge() for that use-case

In the same vein as some earlier patches like f546d2170b0f (merge:
introduce a clean_update() for that use-case, 2020-01-15).

Differential Revision: https://phab.mercurial-scm.org/D8168

Checking the size/permissions/file-type of files stored in the
dirstate after an update where the files are changed concurrently
outside of hg's control.

  $ hg init repo
  $ cd repo
  $ echo a > a
  $ hg commit -qAm _
  $ echo aa > a
  $ hg commit -m _

  $ hg debugdirstate --no-dates
  n 644          3 (set  |unset)               a (re)

  $ cat >> $TESTTMP/dirstaterace.py << EOF
  > from mercurial import (
  >     extensions,
  >     merge,
  > )
  > def extsetup(ui):
  >     extensions.wrapfunction(merge, 'applyupdates', wrap)
  > def wrap(orig, *args, **kwargs):
  >     res = orig(*args, **kwargs)
  >     with open("a", "w"):
  >         pass # just truncate the file
  >     return res
  > EOF

Do an update where file 'a' is changed between hg writing it to disk
and hg writing the dirstate. The dirstate is correct nonetheless, and
so hg status correctly shows a as clean.

  $ hg up -r 0 --config extensions.race=$TESTTMP/dirstaterace.py
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg debugdirstate --no-dates
  n 644          2 (set  |unset)               a (re)
  $ echo a > a; hg status; hg diff