view tests/test-narrow-rebase.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

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

create full repo

  $ hg init master
  $ cd master

  $ mkdir inside
  $ echo inside1 > inside/f1
  $ echo inside2 > inside/f2
  $ mkdir outside
  $ echo outside1 > outside/f1
  $ echo outside2 > outside/f2
  $ hg ci -Aqm 'initial'

  $ echo modified > inside/f1
  $ hg ci -qm 'modify inside/f1'

  $ hg update -q 0
  $ echo modified2 > inside/f2
  $ hg ci -qm 'modify inside/f2'

  $ hg update -q 0
  $ echo modified > outside/f1
  $ hg ci -qm 'modify outside/f1'

  $ hg update -q 0
  $ echo modified2 > outside/f1
  $ hg ci -qm 'conflicting outside/f1'

  $ cd ..

  $ hg clone --narrow ssh://user@dummy/master narrow --include inside
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 5 changesets with 4 changes to 2 files (+3 heads)
  new changesets *:* (glob)
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd narrow
  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > EOF

  $ hg update -q 0

Can rebase onto commit where no files outside narrow spec are involved

  $ hg update -q 0
  $ echo modified > inside/f2
  $ hg ci -qm 'modify inside/f2'
  $ hg rebase -d 'desc("modify inside/f1")'
  rebasing 5:c2f36d04e05d "modify inside/f2" (tip)
  saved backup bundle to $TESTTMP/narrow/.hg/strip-backup/*-rebase.hg (glob)

Can rebase onto conflicting changes inside narrow spec

  $ hg update -q 0
  $ echo conflicting > inside/f1
  $ hg ci -qm 'conflicting inside/f1'
  $ hg rebase -d 'desc("modify inside/f1")' 2>&1 | egrep -v '(warning:|incomplete!)'
  rebasing 6:cdce97fbf653 "conflicting inside/f1" (tip)
  merging inside/f1
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  $ echo modified3 > inside/f1
  $ hg resolve -m 2>&1 | grep -v continue:
  (no more unresolved files)
  $ hg rebase --continue
  rebasing 6:cdce97fbf653 "conflicting inside/f1" (tip)
  saved backup bundle to $TESTTMP/narrow/.hg/strip-backup/*-rebase.hg (glob)

Can rebase onto non-conflicting changes outside narrow spec

  $ hg update -q 0
  $ echo modified > inside/f2
  $ hg ci -qm 'modify inside/f2'
  $ hg rebase -d 'desc("modify outside/f1")'
  rebasing 7:c2f36d04e05d "modify inside/f2" (tip)
  saved backup bundle to $TESTTMP/narrow/.hg/strip-backup/*-rebase.hg (glob)

Rebase interrupts on conflicting changes outside narrow spec

  $ hg update -q 'desc("conflicting outside/f1")'
  $ hg phase -f -d .
  $ hg rebase -d 'desc("modify outside/f1")'
  rebasing 4:707c035aadb6 "conflicting outside/f1"
  abort: conflict in file 'outside/f1' is outside narrow clone
  [255]