tests/test-subrepo-missing.t

scmutil: add file object wrapper class to check ambiguity at closing

In Mercurial source tree, opening a file in "a"/"a+" mode like below
doesn't specify atomictemp=True for vfs, and this avoids file stat
ambiguity check by atomictempfile.

  - writing changes out in revlog layer uses "a+" mode
  - truncation in repair.strip() uses "a" mode
  - truncation in transaction._playback() uses "a" mode

If steps below occurs at "the same time in sec", all of mtime, ctime
and size are same between (1) and (3).

  1. append data to revlog-style file (and close transaction)
  2. discard appended data by truncation (strip or rollback)
  3. append same size but different data to revlog-style file again

Therefore, cache validation doesn't work after (3) as expected.

This patch adds file object wrapper class checkambigatclosing to check
(and get rid of) ambiguity at closing. It is used by vfs in subsequent
patch.

This is a part of ExactCacheValidationPlan.

    https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan

BTW, checkambigatclosing is tested in test-filecache.py, even though
it doesn't use filecache itself, because filecache assumes that file
stat ambiguity never occurs (and there is no another test-*.py related
to filecache).

  $ hg init repo
  $ cd repo
  $ hg init subrepo
  $ echo a > subrepo/a
  $ hg -R subrepo ci -Am adda
  adding a
  $ echo 'subrepo = subrepo' > .hgsub
  $ hg ci -Am addsubrepo
  adding .hgsub
  $ echo b > subrepo/b
  $ hg -R subrepo ci -Am addb
  adding b
  $ hg ci -m updatedsub

ignore blanklines in .hgsubstate

  >>> file('.hgsubstate', 'wb').write('\n\n   \t \n   \n')
  $ hg st --subrepos
  M .hgsubstate
  $ hg revert -qC .hgsubstate

abort more gracefully on .hgsubstate parsing error

  $ cp .hgsubstate .hgsubstate.old
  >>> file('.hgsubstate', 'wb').write('\ninvalid')
  $ hg st --subrepos --cwd $TESTTMP -R $TESTTMP/repo
  abort: invalid subrepository revision specifier in 'repo/.hgsubstate' line 2
  [255]
  $ mv .hgsubstate.old .hgsubstate

delete .hgsub and revert it

  $ rm .hgsub
  $ hg revert .hgsub
  warning: subrepo spec file '.hgsub' not found
  warning: subrepo spec file '.hgsub' not found
  warning: subrepo spec file '.hgsub' not found

delete .hgsubstate and revert it

  $ rm .hgsubstate
  $ hg revert .hgsubstate

delete .hgsub and update

  $ rm .hgsub
  $ hg up 0 --cwd $TESTTMP -R $TESTTMP/repo
  warning: subrepo spec file 'repo/.hgsub' not found
  warning: subrepo spec file 'repo/.hgsub' not found
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg st
  warning: subrepo spec file '.hgsub' not found
  ! .hgsub
  $ ls subrepo
  a

delete .hgsubstate and update

  $ hg up -C
  warning: subrepo spec file '.hgsub' not found
  warning: subrepo spec file '.hgsub' not found
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm .hgsubstate
  $ hg up 0
  other [destination] changed .hgsubstate which local [working copy] deleted
  use (c)hanged version or leave (d)eleted? c
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg st
  $ ls subrepo
  a

Enable obsolete

  $ cat >> $HGRCPATH << EOF
  > [ui]
  > logtemplate= {rev}:{node|short} {desc|firstline}
  > [phases]
  > publish=False
  > [experimental]
  > evolution=createmarkers
  > EOF

check that we can update parent repo with missing (amended) subrepo revision

  $ hg up --repository subrepo -r tip
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg ci -m "updated subrepo to tip"
  created new head
  $ cd subrepo
  $ hg update -r tip
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo foo > a
  $ hg commit --amend -m "addb (amended)"
  $ cd ..
  $ hg update --clean .
  revision 102a90ea7b4a in subrepo subrepo is hidden
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

check that --hidden is propagated to the subrepo

  $ hg -R subrepo up tip
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg ci -m 'commit with amended subrepo'
  $ echo bar > subrepo/a
  $ hg -R subrepo ci --amend -m "amend a (again)"
  $ hg --hidden cat subrepo/a
  foo

verify will warn if locked-in subrepo revisions are hidden or missing

  $ hg ci -m "amended subrepo (again)"
  $ hg --config extensions.strip= --hidden strip -R subrepo -qr 'tip'
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  2 files, 5 changesets, 5 total revisions
  checking subrepo links
  subrepo 'subrepo' is hidden in revision a66de08943b6
  subrepo 'subrepo' is hidden in revision 674d05939c1e
  subrepo 'subrepo' not found in revision a7d05d9055a4

verifying shouldn't init a new subrepo if the reference doesn't exist

  $ mv subrepo b
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  2 files, 5 changesets, 5 total revisions
  checking subrepo links
  0: repository $TESTTMP/repo/subrepo not found (glob)
  1: repository $TESTTMP/repo/subrepo not found (glob)
  3: repository $TESTTMP/repo/subrepo not found (glob)
  4: repository $TESTTMP/repo/subrepo not found (glob)
  $ ls
  b
  $ mv b subrepo

  $ cd ..