view tests/test-dirstate-race2.t @ 47294:93a0abe098e7

revlog: avoid raising no-arg RevlogError for internal flow control

I'm about to make RevlogError require a `message` argument and this
code was failing. This patch refactors it to not raise an exception
for intra-function flow control.

Differential Revision: https://phab.mercurial-scm.org/D10740

#testcases dirstate-v1 dirstate-v1-tree dirstate-v2

#if dirstate-v1-tree
#require rust
  $ echo '[experimental]' >> $HGRCPATH
  $ echo 'dirstate-tree.in-memory=1' >> $HGRCPATH
#endif

#if dirstate-v2
#require rust
  $ echo '[format]' >> $HGRCPATH
  $ echo 'exp-dirstate-v2=1' >> $HGRCPATH
#endif

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