view tests/test-remotefilelog-pull-noshallow.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

#require no-windows

  $ . "$TESTDIR/remotefilelog-library.sh"

Set up an extension to make sure remotefilelog clientsetup() runs
unconditionally even if we have never used a local shallow repo.
This mimics behavior when using remotefilelog with chg.  clientsetup() can be
triggered due to a shallow repo, and then the code can later interact with
non-shallow repositories.

  $ cat > setupremotefilelog.py << EOF
  > from mercurial import extensions
  > def extsetup(ui):
  >     remotefilelog = extensions.find(b'remotefilelog')
  >     remotefilelog.onetimeclientsetup(ui)
  > EOF

Set up the master repository to pull from.

  $ hg init master
  $ cd master
  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > server=True
  > EOF
  $ echo x > x
  $ hg commit -qAm x

  $ cd ..

  $ hg clone ssh://user@dummy/master child -q

We should see the remotefilelog capability here, which advertises that
the server supports our custom getfiles method.

  $ cd master
  $ echo 'hello' | hg -R . serve --stdio | grep capa | identifyrflcaps
  exp-remotefilelog-ssh-getfiles-1
  x_rfl_getfile
  x_rfl_getflogheads
  $ echo 'capabilities' | hg -R . serve --stdio | identifyrflcaps ; echo
  exp-remotefilelog-ssh-getfiles-1
  x_rfl_getfile
  x_rfl_getflogheads
  

Pull to the child repository.  Use our custom setupremotefilelog extension
to ensure that remotefilelog.onetimeclientsetup() gets triggered.  (Without
using chg it normally would not be run in this case since the local repository
is not shallow.)

  $ echo y > y
  $ hg commit -qAm y

  $ cd ../child
  $ hg pull --config extensions.setuprfl=$TESTTMP/setupremotefilelog.py
  pulling from ssh://user@dummy/master
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets d34c38483be9
  (run 'hg update' to get a working copy)

  $ hg up
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cat y
  y

Test that bundle works in a non-remotefilelog repo w/ remotefilelog loaded

  $ echo y >> y
  $ hg commit -qAm "modify y"
  $ hg bundle --base ".^" --rev . mybundle.hg --config extensions.setuprfl=$TESTTMP/setupremotefilelog.py
  1 changesets found

  $ cd ..