view tests/test-parents.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.

test parents command

  $ hg init repo
  $ cd repo

no working directory

  $ hg parents

  $ echo a > a
  $ echo b > b
  $ hg ci -Amab -d '0 0'
  adding a
  adding b
  $ echo a >> a
  $ hg ci -Ama -d '1 0'
  $ echo b >> b
  $ hg ci -Amb -d '2 0'
  $ echo c > c
  $ hg ci -Amc -d '3 0'
  adding c
  $ hg up -C 1
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo d > c
  $ hg ci -Amc2 -d '4 0'
  adding c
  created new head
  $ hg up -C 3
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved


  $ hg parents
  changeset:   3:02d851b7e549
  user:        test
  date:        Thu Jan 01 00:00:03 1970 +0000
  summary:     c
  

  $ hg parents a
  changeset:   1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     a
  

hg parents c, single revision

  $ hg parents c
  changeset:   3:02d851b7e549
  user:        test
  date:        Thu Jan 01 00:00:03 1970 +0000
  summary:     c
  

  $ hg parents -r 3 c
  abort: 'c' not found in manifest!
  [255]

  $ hg parents -r 2
  changeset:   1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     a
  

  $ hg parents -r 2 a
  changeset:   1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     a
  

  $ hg parents -r 2 ../a
  abort: ../a not under root '$TESTTMP/repo' (glob)
  [255]


cd dir; hg parents -r 2 ../a

  $ mkdir dir
  $ cd dir
  $ hg parents -r 2 ../a
  changeset:   1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     a
  
  $ hg parents -r 2 path:a
  changeset:   1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     a
  
  $ cd ..

  $ hg parents -r 2 glob:a
  abort: can only specify an explicit filename
  [255]


merge working dir with 2 parents, hg parents c

  $ HGMERGE=true hg merge
  merging c
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg parents c
  changeset:   3:02d851b7e549
  user:        test
  date:        Thu Jan 01 00:00:03 1970 +0000
  summary:     c
  
  changeset:   4:48cee28d4b4e
  tag:         tip
  parent:      1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  summary:     c2
  


merge working dir with 1 parent, hg parents

  $ hg up -C 2
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ HGMERGE=true hg merge -r 4
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg parents
  changeset:   2:6cfac479f009
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     b
  
  changeset:   4:48cee28d4b4e
  tag:         tip
  parent:      1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  summary:     c2
  

merge working dir with 1 parent, hg parents c

  $ hg parents c
  changeset:   4:48cee28d4b4e
  tag:         tip
  parent:      1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  summary:     c2
  

  $ cd ..