view tests/test-obsolete-changeset-exchange.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 changesets filtering during exchanges (some tests are still in
test-obsolete.t)

  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > evolution=createmarkers
  > EOF

Push does not corrupt remote
----------------------------

Create a DAG where a changeset reuses a revision from a file first used in an
extinct changeset.

  $ hg init local
  $ cd local
  $ echo 'base' > base
  $ hg commit -Am base
  adding base
  $ echo 'A' > A
  $ hg commit -Am A
  adding A
  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg revert -ar 1
  adding A
  $ hg commit -Am "A'"
  created new head
  $ hg log -G --template='{desc} {node}'
  @  A' f89bcc95eba5174b1ccc3e33a82e84c96e8338ee
  |
  | o  A 9d73aac1b2ed7d53835eaeec212ed41ea47da53a
  |/
  o  base d20a80d4def38df63a4b330b7fb688f3d4cae1e3
  
  $ hg debugobsolete 9d73aac1b2ed7d53835eaeec212ed41ea47da53a f89bcc95eba5174b1ccc3e33a82e84c96e8338ee

Push it. The bundle should not refer to the extinct changeset.

  $ hg init ../other
  $ hg push ../other
  pushing to ../other
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files
  $ hg -R ../other verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  2 files, 2 changesets, 2 total revisions

Adding a changeset going extinct locally
------------------------------------------

Pull a changeset that will immediatly goes extinct (because you already have a
marker to obsolete him)
(test resolution of issue3788)

  $ hg phase --draft --force f89bcc95eba5
  $ hg phase -R ../other --draft --force f89bcc95eba5
  $ hg commit --amend -m "A''"
  $ hg --hidden --config extensions.mq= strip  --no-backup f89bcc95eba5
  $ hg pull ../other
  pulling from ../other
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 1 files (+1 heads)
  (run 'hg heads' to see heads, 'hg merge' to merge)

check that bundle is not affected

  $ hg bundle --hidden --rev f89bcc95eba5 --base "f89bcc95eba5^" ../f89bcc95eba5.hg
  1 changesets found
  $ hg --hidden --config extensions.mq= strip --no-backup f89bcc95eba5
  $ hg unbundle ../f89bcc95eba5.hg
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 1 files (+1 heads)
  (run 'hg heads' to see heads)