view tests/test-remotefilelog-clone.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"

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

  $ cd ..

# shallow clone from full

  $ hgcloneshallow ssh://user@dummy/master shallow --noupdate
  streaming all changes
  2 files to transfer, 227 bytes of data
  transferred 227 bytes in * seconds (*/sec) (glob)
  searching for changes
  no changes found
  $ cd shallow
  $ cat .hg/requires
  dotencode
  exp-remotefilelog-repo-req-1
  fncache
  generaldelta
  revlogv1
  sparserevlog
  store

  $ hg update
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)

  $ cat x
  x

  $ ls .hg/store/data
  $ echo foo > f
  $ hg add f
  $ hg ci -m 'local content'
  $ ls .hg/store/data
  4a0a19218e082a343a1b17e5333409af9d98f0f5

  $ cd ..

# shallow clone from shallow

  $ hgcloneshallow ssh://user@dummy/shallow shallow2  --noupdate
  streaming all changes
  3 files to transfer, 564 bytes of data
  transferred 564 bytes in * seconds (*/sec) (glob)
  searching for changes
  no changes found
  $ cd shallow2
  $ cat .hg/requires
  dotencode
  exp-remotefilelog-repo-req-1
  fncache
  generaldelta
  revlogv1
  sparserevlog
  store
  $ ls .hg/store/data
  4a0a19218e082a343a1b17e5333409af9d98f0f5

  $ hg update
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cat x
  x

  $ cd ..

# full clone from shallow

Note: the output to STDERR comes from a different process to the output on
STDOUT and their relative ordering is not deterministic. As a result, the test
was failing sporadically. To avoid this, we capture STDERR to a file and
check its contents separately.

  $ TEMP_STDERR=full-clone-from-shallow.stderr.tmp
  $ hg clone --noupdate ssh://user@dummy/shallow full 2>$TEMP_STDERR
  streaming all changes
  remote: abort: Cannot clone from a shallow repo to a full repo.
  [255]
  $ cat $TEMP_STDERR
  abort: pull failed on remote
  $ rm $TEMP_STDERR

# getbundle full clone

  $ printf '[server]\npreferuncompressed=False\n' >> master/.hg/hgrc
  $ hgcloneshallow ssh://user@dummy/master shallow3
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files
  new changesets b292c1e3311f
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ ls shallow3/.hg/store/data
  $ cat shallow3/.hg/requires
  dotencode
  exp-remotefilelog-repo-req-1
  fncache
  generaldelta
  revlogv1
  sparserevlog
  store