view tests/test-branch-change.t @ 40056:324b4b10351e

revlog: rewrite censoring logic

I was able to corrupt a revlog relatively easily with the existing
censoring code. The underlying problem is that the existing code
doesn't fully take delta chains into account. When copying revisions
that occur after the censored revision, the delta base can refer
to a censored revision. Then at read time, things blow up due to the
revision data not being a compressed delta.

This commit rewrites the revlog censoring code to take a higher-level
approach. We now create a new revlog instance pointing at temp files.
We iterate through each revision in the source revlog and insert
those revisions into the new revlog, replacing the censored revision's
data along the way.

The new implementation isn't as efficient as the old one. This is
because it will fully engage delta computation on insertion. But I
don't think it matters.

The new implementation is a bit hacky because it attempts to reload
the revlog instance with a new revlog index/data file. This is fragile.
But this is needed because the index (which could be backed by C) would
have a cached copy of the old, possibly changed data and that could
lead to problems accessing index or revision data later.

One benefit of the new approach is that we integrate with the
transaction. The old revlog is backed up and if the transaction is
rolled back, the original revlog is restored.

As part of this, we had to teach the transaction about the store
vfs. I'm not super keen about this. But this was the easiest way
to hook things up to the transaction. We /could/ just ignore the
transaction like we were doing before. But any file mutation should
be governed by transaction semantics, including undo during rollback.

Differential Revision: https://phab.mercurial-scm.org/D4869

Testing changing branch on commits
==================================

Setup

  $ cat >> $HGRCPATH << EOF
  > [alias]
  > glog = log -G -T "{rev}:{node|short} {desc}\n{branch} ({bookmarks})"
  > [experimental]
  > evolution = createmarkers
  > [extensions]
  > rebase=
  > EOF

  $ hg init repo
  $ cd repo
  $ for ch in a b c d e; do echo foo >> $ch; hg ci -Aqm "Added "$ch; done
  $ hg glog
  @  4:aa98ab95a928 Added e
  |  default ()
  o  3:62615734edd5 Added d
  |  default ()
  o  2:28ad74487de9 Added c
  |  default ()
  o  1:29becc82797a Added b
  |  default ()
  o  0:18d04c59bb5d Added a
     default ()

  $ hg branches
  default                        4:aa98ab95a928

Try without passing a new branch name

  $ hg branch -r .
  abort: no branch name specified for the revisions
  [255]

Setting an invalid branch name

  $ hg branch -r . a:b
  abort: ':' cannot be used in a name
  [255]
  $ hg branch -r . tip
  abort: the name 'tip' is reserved
  [255]
  $ hg branch -r . 1234
  abort: cannot use an integer as a name
  [255]

Change on non-linear set of commits

  $ hg branch -r 2 -r 4 foo
  abort: cannot change branch of non-linear revisions
  [255]

Change in middle of the stack (linear commits)

  $ hg branch -r 1::3 foo
  abort: cannot change branch of changeset with children
  [255]

Change with dirty working directory

  $ echo bar > a
  $ hg branch -r . foo
  abort: uncommitted changes
  [255]

  $ hg revert --all
  reverting a

Change on empty revision set

  $ hg branch -r 'draft() - all()' foo
  abort: empty revision set
  [255]

Changing branch on linear set of commits from head

Without obsmarkers

  $ hg branch -r 3:4 foo --config experimental.evolution=!
  changed branch on 2 changesets
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/62615734edd5-e86bd13a-branch-change.hg
  $ hg glog
  @  4:3938acfb5c0f Added e
  |  foo ()
  o  3:9435da006bdc Added d
  |  foo ()
  o  2:28ad74487de9 Added c
  |  default ()
  o  1:29becc82797a Added b
  |  default ()
  o  0:18d04c59bb5d Added a
     default ()

  $ hg branches
  foo                            4:3938acfb5c0f
  default                        2:28ad74487de9 (inactive)

With obsmarkers

  $ hg branch -r 3::4 bar
  changed branch on 2 changesets
  $ hg glog
  @  6:7c1991464886 Added e
  |  bar ()
  o  5:1ea05e93925f Added d
  |  bar ()
  o  2:28ad74487de9 Added c
  |  default ()
  o  1:29becc82797a Added b
  |  default ()
  o  0:18d04c59bb5d Added a
     default ()

  $ hg branches
  bar                            6:7c1991464886
  default                        2:28ad74487de9 (inactive)

Change branch name to an existing branch

  $ hg branch -r . default
  abort: a branch of the same name already exists
  [255]

Changing on a branch head which is not topological head

  $ hg branch -r 2 stable
  abort: cannot change branch of changeset with children
  [255]

Enabling the allowunstable config and trying to change branch on a branch head
which is not a topological head

  $ echo "[experimental]" >> .hg/hgrc
  $ echo "evolution.allowunstable=yes" >> .hg/hgrc
  $ hg branch -r 2 foo
  changed branch on 1 changesets
  2 new orphan changesets

Changing branch of an obsoleted changeset

  $ hg branch -r 4 foobar
  abort: hidden revision '4' was rewritten as: 7c1991464886!
  (use --hidden to access hidden revisions)
  [255]

  $ hg branch -r 4 --hidden foobar
  abort: cannot change branch of a obsolete changeset
  [255]

Make sure bookmark movement is correct

  $ hg bookmark b1
  $ hg glog -r '.^::'
  @  6:7c1991464886 Added e
  |  bar (b1)
  *  5:1ea05e93925f Added d
  |  bar ()
  ~

  $ hg branch -r '(.^)::' wat --debug
  changing branch of '1ea05e93925f806d875a2163f9b76764be644636' from 'bar' to 'wat'
  committing files:
  d
  committing manifest
  committing changelog
  new node id is 343660ccab7400da637bd6a211d07f413536d718
  changing branch of '7c19914648869f5b02fc7fed31ddee9783fdd680' from 'bar' to 'wat'
  committing files:
  e
  committing manifest
  committing changelog
  new node id is de1404b45a69f8cc6437d7679033ee33e9efb4ba
  moving bookmarks ['b1'] from 7c19914648869f5b02fc7fed31ddee9783fdd680 to de1404b45a69f8cc6437d7679033ee33e9efb4ba
  resolving manifests
   branchmerge: False, force: False, partial: False
   ancestor: 7c1991464886, local: 7c1991464886+, remote: de1404b45a69
  starting 4 threads for background file closing (?)
  changed branch on 2 changesets
  updating the branch cache
  invalid branchheads cache (served): tip differs

  $ hg glog -r '(.^)::'
  @  9:de1404b45a69 Added e
  |  wat (b1)
  *  8:343660ccab74 Added d
  |  wat ()
  ~

Make sure phase handling is correct

  $ echo foo >> bar
  $ hg ci -Aqm "added bar" --secret
  1 new orphan changesets
  $ hg glog -r .
  @  10:8ad1294c1660 added bar
  |  wat (b1)
  ~
  $ hg branch -r . secret
  changed branch on 1 changesets
  $ hg phase -r .
  11: secret

  $ hg branches
  secret                        11:38a9b2d53f98
  foo                            7:8a4729a5e2b8
  wat                            9:de1404b45a69 (inactive)
  default                        2:28ad74487de9 (inactive)
  $ hg branch
  secret

Changing branch of another head, different from one on which we are

  $ hg glog
  @  11:38a9b2d53f98 added bar
  |  secret (b1)
  *  9:de1404b45a69 Added e
  |  wat ()
  *  8:343660ccab74 Added d
  |  wat ()
  | o  7:8a4729a5e2b8 Added c
  | |  foo ()
  x |  2:28ad74487de9 Added c
  |/   default ()
  o  1:29becc82797a Added b
  |  default ()
  o  0:18d04c59bb5d Added a
     default ()

  $ hg branch
  secret

  $ hg branch -r 7 foobar
  changed branch on 1 changesets

The current branch must be preserved
  $ hg branch
  secret

Changing branch on multiple heads at once

  $ hg rebase -s 8 -d 12 --keepbranches -q

  $ hg rebase -s 14 -d 1 --keepbranches -q

  $ hg branch -r 0: stable
  changed branch on 6 changesets
  $ hg glog
  @  23:6a5ddbcfb870 added bar
  |  stable (b1)
  o  22:baedc6e98a67 Added e
  |  stable ()
  | o  21:99ac7bf8aad1 Added d
  | |  stable ()
  | o  20:0ecb4d39c4bd Added c
  |/   stable ()
  o  19:fd45b986b109 Added b
  |  stable ()
  o  18:204d2769eca2 Added a
     stable ()

  $ hg branches
  stable                        23:6a5ddbcfb870

  $ hg branch
  stable

Changing to same branch is no-op

  $ hg branch -r 19::21 stable
  changed branch on 0 changesets

Changing branch name to existing branch name if the branch of parent of root of
revs is same as the new branch name

  $ hg branch -r 20::21 bugfix
  changed branch on 2 changesets
  $ hg glog
  o  25:714defe1cf34 Added d
  |  bugfix ()
  o  24:98394def28fc Added c
  |  bugfix ()
  | @  23:6a5ddbcfb870 added bar
  | |  stable (b1)
  | o  22:baedc6e98a67 Added e
  |/   stable ()
  o  19:fd45b986b109 Added b
  |  stable ()
  o  18:204d2769eca2 Added a
     stable ()

  $ hg branch -r 24:25 stable
  changed branch on 2 changesets
  $ hg glog
  o  27:4ec342341562 Added d
  |  stable ()
  o  26:83f48859c2de Added c
  |  stable ()
  | @  23:6a5ddbcfb870 added bar
  | |  stable (b1)
  | o  22:baedc6e98a67 Added e
  |/   stable ()
  o  19:fd45b986b109 Added b
  |  stable ()
  o  18:204d2769eca2 Added a
     stable ()

Testing on merge

  $ hg merge -r 26
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg branch -r . abcd
  abort: outstanding uncommitted merge
  [255]
  $ hg ci -m "Merge commit"
  $ hg branch -r '(.^)::' def
  abort: cannot change branch of a merge commit
  [255]

Changing branch on public changeset

  $ hg phase -r 27 -p
  $ hg branch -r 27 def
  abort: cannot change branch of public changesets
  (see 'hg help phases' for details)
  [255]