view tests/test-pull-branch.t @ 42377:0546ead39a7e stable

manifest: avoid corruption by dropping removed files with pure (issue5801)

Previously, removed files would simply be marked by overwriting the first byte
with NUL and dropping their entry in `self.position`.  But no effort was made to
ignore them when compacting the dictionary into text form.  This allowed them to
slip into the manifest revision, since the code seems to be trying to minimize
the string operations by copying as large a chunk as possible.  As part of this,
compact() walks the existing text based on entries in the `positions` list, and
consumed everything up to the next position entry.   This typically resulted in
a ValueError complaining about unsorted manifest entries.

Sometimes it seems that files do get dropped in large repos- it seems to
correspond to there being a new entry that would take the same slot.  A much
more trivial problem is that if the only changes were removals, `_compact()`
didn't even run because `__delitem__` doesn't add anything to `self.extradata`.
Now there's an explicit variable to flag this, both to allow `_compact()` to
run, and to avoid searching the manifest in cases where there are no removals.

In practice, this behavior was mostly obscured by the check in fastdelta() which
takes a different path that explicitly drops removed files if there are fewer
than 1000 changes.  However, timeless has a repo where after rebasing tens of
commits, a totally different path[1] is taken that bypasses the change count
check and hits this problem.

[1] https://www.mercurial-scm.org/repo/hg/file/2338bdea4474/mercurial/manifest.py#l1511

  $ hg init t
  $ cd t
  $ echo 1 > foo
  $ hg ci -Am1 # 0
  adding foo
  $ hg branch branchA
  marked working directory as branch branchA
  (branches are permanent and global, did you want a bookmark?)
  $ echo a1 > foo
  $ hg ci -ma1 # 1

  $ cd ..
  $ hg init tt
  $ cd tt
  $ hg pull ../t
  pulling from ../t
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files
  new changesets 495a0ec48aaf:50e089d141b7
  (run 'hg update' to get a working copy)
  $ hg up branchA
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd ../t
  $ echo a2 > foo
  $ hg ci -ma2 # 2

Create branch B:

  $ hg up 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg branch branchB
  marked working directory as branch branchB
  $ echo b1 > foo
  $ hg ci -mb1 # 3

  $ cd ../tt

A new branch is there

  $ hg pull -u ../t
  pulling from ../t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files (+1 heads)
  new changesets 9f878dea0b96:5be59ce5067b
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

Develop both branches:

  $ cd ../t
  $ hg up branchA
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a3 > foo
  $ hg ci -ma3 # 4
  $ hg up branchB
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b2 > foo
  $ hg ci -mb2 # 5

  $ cd ../tt

Should succeed, no new heads:

  $ hg pull -u ../t
  pulling from ../t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files
  new changesets 7c8fe7e20c32:453e93fa00a5
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

Add a head on other branch:

  $ cd ../t
  $ hg up branchA
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a4 > foo
  $ hg ci -ma4 # 6
  $ hg up branchB
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b3.1 > foo
  $ hg ci -m b3.1 # 7
  $ hg up 5
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b3.2 > foo
  $ hg ci -m b3.2 # 8
  created new head

  $ cd ../tt

Should succeed because there is only one head on our branch:

  $ hg pull -u ../t
  pulling from ../t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 1 files (+1 heads)
  new changesets da3a8a0161c6:b61cab8fe4e8
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd ../t
  $ hg up -C branchA
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a5.1 > foo
  $ hg ci -ma5.1 # 9
  $ hg up 6
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a5.2 > foo
  $ hg ci -ma5.2 # 10
  created new head
  $ hg up 7
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b4.1 > foo
  $ hg ci -m b4.1 # 11
  $ hg up -C 8
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b4.2 > foo
  $ hg ci -m b4.2 # 12

  $ cd ../tt

  $ hg pull -u ../t
  pulling from ../t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 4 changes to 1 files (+1 heads)
  new changesets 0c4d148ae29e:ecfc3f4a6fd9
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  updated to "d740e1a584e7: a5.2"
  1 other heads for branch "branchA"

Make changes on new branch on tt

  $ hg up 6
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg branch branchC
  marked working directory as branch branchC
  $ echo b1 > bar
  $ hg ci -Am "commit on branchC on tt"
  adding bar

Make changes on default branch on t

  $ cd ../t
  $ hg up -C default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a1 > bar
  $ hg ci -Am "commit on default on t"
  adding bar

Pull branchC from tt

  $ hg pull ../tt
  pulling from ../tt
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  new changesets 7d8ffa4c0b22
  13 local changesets published
  (run 'hg heads' to see heads)

Make changes on default and branchC on tt

  $ cd ../tt
  $ hg pull ../t
  pulling from ../t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  new changesets 2b94b54b6b5f
  1 local changesets published
  (run 'hg heads' to see heads)
  $ hg up -C default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a1 > bar1
  $ hg ci -Am "commit on default on tt"
  adding bar1
  $ hg up branchC
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo a1 > bar2
  $ hg ci -Am "commit on branchC on tt"
  adding bar2

Make changes on default and branchC on t

  $ cd ../t
  $ hg up default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a1 > bar3
  $ hg ci -Am "commit on default on t"
  adding bar3
  $ hg up branchC
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo a1 > bar4
  $ hg ci -Am "commit on branchC on tt"
  adding bar4

Pull from tt

  $ hg pull ../tt
  pulling from ../tt
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+2 heads)
  new changesets eed40c14b407:e634733b0309
  1 local changesets published
  (run 'hg heads .' to see heads, 'hg merge' to merge)

  $ cd ..