view tests/test-pull-branch.t @ 32697:19b9fc40cc51

revlog: skeleton support for version 2 revlogs

There are a number of improvements we want to make to revlogs
that will require a new version - version 2. It is unclear what the
full set of improvements will be or when we'll be done with them.
What I do know is that the process will likely take longer than a
single release, will require input from various stakeholders to
evaluate changes, and will have many contentious debates and
bikeshedding.

It is unrealistic to develop revlog version 2 up front: there
are just too many uncertainties that we won't know until things
are implemented and experiments are run. Some changes will also
be invasive and prone to bit rot, so sitting on dozens of patches
is not practical.

This commit introduces skeleton support for version 2 revlogs in
a way that is flexible and not bound by backwards compatibility
concerns.

An experimental repo requirement for denoting revlog v2 has been
added. The requirement string has a sub-version component to it.
This will allow us to declare multiple requirements in the course
of developing revlog v2. Whenever we change the in-development
revlog v2 format, we can tweak the string, creating a new
requirement and locking out old clients. This will allow us to
make as many backwards incompatible changes and experiments to
revlog v2 as we want. In other words, we can land code and make
meaningful progress towards revlog v2 while still maintaining
extreme format flexibility up until the point we freeze the
format and remove the experimental labels.

To enable the new repo requirement, you must supply an experimental
and undocumented config option. But not just any boolean flag
will do: you need to explicitly use a value that no sane person
should ever type. This is an additional guard against enabling
revlog v2 on an installation it shouldn't be enabled on. The
specific scenario I'm trying to prevent is say a user with a
4.4 client with a frozen format enabling the option but then
downgrading to 4.3 and accidentally creating repos with an
outdated and unsupported repo format. Requiring a "challenge"
string should prevent this.

Because the format is not yet finalized and I don't want to take
any chances, revlog v2's version is currently 0xDEAD. I figure
squatting on a value we're likely never to use as an actual revlog
version to mean "internal testing only" is acceptable. And
"dead" is easily recognized as something meaningful.

There is a bunch of cleanup that is needed before work on revlog
v2 begins in earnest. I plan on doing that work once this patch
is accepted and we're comfortable with the idea of starting down
this path.

  $ hg init t
  $ cd t
  $ echo 1 > foo
  $ hg ci -Am1 # 0
  adding foo
  $ hg branch branchA
  marked working directory as branch branchA
  (branches are permanent and global, did you want a bookmark?)
  $ echo a1 > foo
  $ hg ci -ma1 # 1

  $ cd ..
  $ hg init tt
  $ cd tt
  $ hg pull ../t
  pulling from ../t
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files
  (run 'hg update' to get a working copy)
  $ hg up branchA
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd ../t
  $ echo a2 > foo
  $ hg ci -ma2 # 2

Create branch B:

  $ hg up 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg branch branchB
  marked working directory as branch branchB
  $ echo b1 > foo
  $ hg ci -mb1 # 3

  $ cd ../tt

A new branch is there

  $ hg pull -u ../t
  pulling from ../t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files (+1 heads)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

Develop both branches:

  $ cd ../t
  $ hg up branchA
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a3 > foo
  $ hg ci -ma3 # 4
  $ hg up branchB
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b2 > foo
  $ hg ci -mb2 # 5

  $ cd ../tt

Should succeed, no new heads:

  $ hg pull -u ../t
  pulling from ../t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

Add a head on other branch:

  $ cd ../t
  $ hg up branchA
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a4 > foo
  $ hg ci -ma4 # 6
  $ hg up branchB
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b3.1 > foo
  $ hg ci -m b3.1 # 7
  $ hg up 5
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b3.2 > foo
  $ hg ci -m b3.2 # 8
  created new head

  $ cd ../tt

Should succeed because there is only one head on our branch:

  $ hg pull -u ../t
  pulling from ../t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 1 files (+1 heads)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd ../t
  $ hg up -C branchA
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a5.1 > foo
  $ hg ci -ma5.1 # 9
  $ hg up 6
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a5.2 > foo
  $ hg ci -ma5.2 # 10
  created new head
  $ hg up 7
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b4.1 > foo
  $ hg ci -m b4.1 # 11
  $ hg up -C 8
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b4.2 > foo
  $ hg ci -m b4.2 # 12

  $ cd ../tt

  $ hg pull -u ../t
  pulling from ../t
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 4 changes to 1 files (+1 heads)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  1 other heads for branch "branchA"

Make changes on new branch on tt

  $ hg up 6
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg branch branchC
  marked working directory as branch branchC
  $ echo b1 > bar
  $ hg ci -Am "commit on branchC on tt"
  adding bar

Make changes on default branch on t

  $ cd ../t
  $ hg up -C default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a1 > bar
  $ hg ci -Am "commit on default on t"
  adding bar

Pull branchC from tt

  $ hg pull ../tt
  pulling from ../tt
  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)

Make changes on default and branchC on tt

  $ cd ../tt
  $ hg pull ../t
  pulling from ../t
  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 up -C default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a1 > bar1
  $ hg ci -Am "commit on default on tt"
  adding bar1
  $ hg up branchC
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo a1 > bar2
  $ hg ci -Am "commit on branchC on tt"
  adding bar2

Make changes on default and branchC on t

  $ cd ../t
  $ hg up default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a1 > bar3
  $ hg ci -Am "commit on default on t"
  adding bar3
  $ hg up branchC
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo a1 > bar4
  $ hg ci -Am "commit on branchC on tt"
  adding bar4

Pull from tt

  $ hg pull ../tt
  pulling from ../tt
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+2 heads)
  (run 'hg heads .' to see heads, 'hg merge' to merge)

  $ cd ..