annotate tests/test-mq-symlinks.t @ 26631:e077ce385609

localrepo: restore dirstate to one before rollbacking if not parent-gone

'localrepository.rollback()' explicilty restores dirstate, only if at
least one of current parents of the working directory is removed at
rollbacking (a.k.a "parent-gone").

After DirstateTransactionPlan, 'dirstate.write()' will cause marking
'.hg/dirstate' as a file to be restored at rollbacking.

    https://mercurial.selenic.com/wiki/DirstateTransactionPlan

Then, 'transaction.rollback()' restores '.hg/dirstate' regardless of
parents of the working directory at that time, and this causes
unexpected dirstate changes if not "parent-gone" (e.g.  "hg update" to
another branch after "hg commit" or so, then "hg rollback").

To avoid such situation, this patch restores dirstate to one before
rollbacking if not "parent-gone".

  before:
    b1. restore dirstate explicitly, if "parent-gone"

  after:
    a1. save dirstate before actual rollbacking via dirstateguard
    a2. restore dirstate via 'transaction.rollback()'
    a3. if "parent-gone"
        - discard backup (a1)
        - restore dirstate from 'undo.dirstate'
    a4. otherwise, restore dirstate from backup (a1)

Even though restoring dirstate at (a3) after (a2) seems redundant,
this patch keeps this existing code path, because:

  - it isn't ensured that 'dirstate.write()' was invoked at least once
    while transaction running

    If not, '.hg/dirstate' isn't restored at (a2).

    In addition to it, rude 3rd party extension invoking
    'dirstate.write()' without 'repo' while transaction running (see
    subsequent patches for detail) may break consistency of a file
    backup-ed by transaction.

  - this patch mainly focuses on changes for DirstateTransactionPlan

    Restoring dirstate at (a3) itself should be cheaper enough than
    rollbacking itself. Redundancy will be removed in next step.

Newly added test is almost meaningless at this point. It will be used
to detect regression while implementing delayed dirstate write out.

#require symlink

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ hg init
  $ hg qinit
  $ hg qnew base.patch
  $ echo aaa > a
  $ echo bbb > b
  $ echo ccc > c
  $ hg add a b c
  $ hg qrefresh
  $ readlink.py a
  a -> a not a symlink


test replacing a file with a symlink

  $ hg qnew symlink.patch
  $ rm a
  $ ln -s b a
  $ hg qrefresh --git
  $ readlink.py a
  a -> b

  $ hg qpop
  popping symlink.patch
  now at: base.patch
  $ hg qpush
  applying symlink.patch
  now at: symlink.patch
  $ readlink.py a
  a -> b


test updating a symlink

  $ rm a
  $ ln -s c a
  $ hg qnew --git -f updatelink
  $ readlink.py a
  a -> c
  $ hg qpop
  popping updatelink
  now at: symlink.patch
  $ hg qpush --debug
  applying updatelink
  patching file a
  committing files:
  a
  committing manifest
  committing changelog
  now at: updatelink
  $ readlink.py a
  a -> c
  $ hg st


test replacing a symlink with a file

  $ ln -s c s
  $ hg add s
  $ hg qnew --git -f addlink
  $ rm s
  $ echo sss > s
  $ hg qnew --git -f replacelinkwithfile
  $ hg qpop
  popping replacelinkwithfile
  now at: addlink
  $ hg qpush
  applying replacelinkwithfile
  now at: replacelinkwithfile
  $ cat s
  sss
  $ hg st


test symlink removal

  $ hg qnew removesl.patch
  $ hg rm a
  $ hg qrefresh --git
  $ hg qpop
  popping removesl.patch
  now at: replacelinkwithfile
  $ hg qpush
  applying removesl.patch
  now at: removesl.patch
  $ hg st -c
  C b
  C c
  C s

replace broken symlink with another broken symlink

  $ ln -s linka linka
  $ hg add linka
  $ hg qnew link
  $ hg mv linka linkb
  $ rm linkb
  $ ln -s linkb linkb
  $ hg qnew movelink
  $ hg qpop
  popping movelink
  now at: link
  $ hg qpush
  applying movelink
  now at: movelink
  $ readlink.py linkb
  linkb -> linkb