view tests/test-issue522.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.

http://mercurial.selenic.com/bts/issue522

In the merge below, the file "foo" has the same contents in both
parents, but if we look at the file-level history, we'll notice that
the version in p1 is an ancestor of the version in p2. This test makes
sure that we'll use the version from p2 in the manifest of the merge
revision.

  $ hg init

  $ echo foo > foo
  $ hg ci -qAm 'add foo'

  $ echo bar >> foo
  $ hg ci -m 'change foo'

  $ hg backout -r tip -m 'backout changed foo'
  reverting foo
  changeset 2:4d9e78aaceee backs out changeset 1:b515023e500e

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

  $ touch bar
  $ hg ci -qAm 'add bar'

  $ hg merge --debug
    searching for copies back to rev 1
    unmatched files in local:
     bar
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: bbd179dfa0a7, local: 71766447bdbb+, remote: 4d9e78aaceee
   foo: remote is newer -> g
  getting foo
  updating: foo 1/1 files (100.00%)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg debugstate | grep foo
  m   0         -2 unset               foo

  $ hg st -A foo
  M foo

  $ hg ci -m 'merge'

  $ hg manifest --debug | grep foo
  c6fc755d7e68f49f880599da29f15add41f42f5a 644   foo

  $ hg debugindex foo
     rev    offset  length  ..... linkrev nodeid       p1           p2 (re)
       0         0       5  .....       0 2ed2a3912a0b 000000000000 000000000000 (re)
       1         5       9  .....       1 6f4310b00b9a 2ed2a3912a0b 000000000000 (re)
       2        14       5  .....       2 c6fc755d7e68 6f4310b00b9a 000000000000 (re)