view tests/test-pull-pull-corruption.t @ 24787:9d5c27890790

largefiles: for update -C, only update largefiles when necessary

Before, a --clean update with largefiles would use the "optimization" that it
didn't read hashes from standin files before and after the update. Instead of
trusting the content of the standin files, it would rehash all the actual
largefiles that lfdirstate reported clean and update the standins that didn't
have the expected content. It could thus in some "impossible" situations
automatically recover from some "largefile got out sync with its standin"
issues (even there apparently still were weird corner cases where it could
fail). This extra checking is similar to what core --clean intentionally do
not do, and it made update --clean unbearable slow.

Usually in core Mercurial, --clean will rely on the dirstate to find the files
it should update. (It is thus intentionally possible (when trying to trick the
system or if there should be bugs) to end up in situations where --clean not
will restore the working directory content correctly.) Checking every file when
we "know" it is ok is however not an option - that would be too slow.

Instead, trust the content of the standin files. Use the same logic for --clean
as for linear updates and trust the dirstate and that our "logic" will keep
them in sync. It is much cheaper to just rehash the largefiles reported dirty
by a status walk and read all standins than to hash largefiles.

Most of the changes are just a change of indentation now when the different
kinds of updates no longer are handled that differently. Standins for added
files are however only written when doing a normal update, while deleted and
removed files only will be updated for --clean updates.

Corrupt an hg repo with two pulls.
create one repo with a long history

  $ hg init source1
  $ cd source1
  $ touch foo
  $ hg add foo
  $ for i in 1 2 3 4 5 6 7 8 9 10; do
  >     echo $i >> foo
  >     hg ci -m $i
  > done
  $ cd ..

create one repo with a shorter history

  $ hg clone -r 0 source1 source2
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd source2
  $ echo a >> foo
  $ hg ci -m a
  $ cd ..

create a third repo to pull both other repos into it

  $ hg init corrupted
  $ cd corrupted

use a hook to make the second pull start while the first one is still running

  $ echo '[hooks]' >> .hg/hgrc
  $ echo 'prechangegroup = sleep 5' >> .hg/hgrc

start a pull...

  $ hg pull ../source1 > pull.out 2>&1 &

... and start another pull before the first one has finished

  $ sleep 1
  $ hg pull ../source2 2>/dev/null
  pulling from ../source2
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ cat pull.out
  pulling from ../source1
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 10 changesets with 10 changes to 1 files
  (run 'hg update' to get a working copy)

see the result

  $ wait
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 11 changesets, 11 total revisions

  $ cd ..