comparison tests/test-manifest.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

42376:89c0c8edc9d4

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > manifest = $TESTTMP/manifest.py
  > EOF

BROKEN: Pure removes should actually remove all dropped entries

  $ hg init repo
  $ cd repo
  $ echo a > a.txt
  $ echo aa > aa.txt

  $ hg ci -m 'remove b and d'

  $ hg debugdata -m 1
  a.txt\x00b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 (esc)
  aa.txt\x00a4bdc161c8fbb523c9a60409603f8710ff49a571 (esc)
  \x00.txt\x001e88685f5ddec574a34c70af492f95b6debc8741 (esc) (pure !)
  c.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)
  cc.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)
  ccc.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)
  \x00.txt\x001e88685f5ddec574a34c70af492f95b6debc8741 (esc) (pure !)
  e.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)

  $ hg up -C . 2>&1 | grep ValueError || true
      raise ValueError("Manifest lines not in sorted order.") (pure !)
  ValueError: Manifest lines not in sorted order. (pure !)

  $ hg verify || true
  checking changesets
  checking manifests
   manifest@1: reading delta c1f6b2f803ac: Non-hexadecimal digit found (pure !)
  crosschecking files in changesets and manifests
  checking files
  checked 2 changesets with 8 changes to 8 files
  1 integrity errors encountered! (pure !)
  (first damaged changeset appears to be 1) (pure !)

  $ hg rollback -q --config ui.rollback=True
  $ hg rm b.txt d.txt
  $ echo bb > bb.txt

BROKEN: A mix of adds and removes should remove all dropped entries.

  $ hg ci -Aqm 'remove b and d; add bb'

  $ hg debugdata -m 1
  a.txt\x00b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 (esc)
  aa.txt\x00a4bdc161c8fbb523c9a60409603f8710ff49a571 (esc)
  bb.txt\x0004c6faf8a9fdd848a5304dfc1704749a374dff44 (esc)
  c.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)
  cc.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)
  ccc.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)
  \x00.txt\x001e88685f5ddec574a34c70af492f95b6debc8741 (esc) (pure !)
  e.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)

  $ hg up -C . 2>&1 | grep ValueError || true
      raise ValueError("Manifest lines not in sorted order.") (pure !)
  ValueError: Manifest lines not in sorted order. (pure !)

  $ hg verify || true
  checking changesets
  checking manifests
   manifest@1: reading delta 0a0385480090: Manifest lines not in sorted order. (pure !)
  crosschecking files in changesets and manifests
   bb.txt@1: in changeset but not in manifest (pure !)
  checking files
  checked 2 changesets with 9 changes to 9 files
  2 integrity errors encountered! (pure !)
  (first damaged changeset appears to be 1) (pure !)

42377:0546ead39a7e

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > manifest = $TESTTMP/manifest.py
  > EOF

Pure removes should actually remove all dropped entries

  $ hg init repo
  $ cd repo
  $ echo a > a.txt
  $ echo aa > aa.txt

  $ hg ci -m 'remove b and d'

  $ hg debugdata -m 1
  a.txt\x00b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 (esc)
  aa.txt\x00a4bdc161c8fbb523c9a60409603f8710ff49a571 (esc)
  c.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)
  cc.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)
  ccc.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)
  e.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)

  $ hg up -qC .

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 2 changesets with 8 changes to 8 files

  $ hg rollback -q --config ui.rollback=True
  $ hg rm b.txt d.txt
  $ echo bb > bb.txt

A mix of adds and removes should remove all dropped entries.

  $ hg ci -Aqm 'remove b and d; add bb'

  $ hg debugdata -m 1
  a.txt\x00b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 (esc)
  aa.txt\x00a4bdc161c8fbb523c9a60409603f8710ff49a571 (esc)
  bb.txt\x0004c6faf8a9fdd848a5304dfc1704749a374dff44 (esc)
  c.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)
  cc.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)
  ccc.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)
  e.txt\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 2 changesets with 9 changes to 9 files