view tests/test-histedit-fold-non-commute.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outdated and unsupported repo format.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.

  $ . "$TESTDIR/histedit-helpers.sh"

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > histedit=
  > EOF

  $ modwithdate ()
  > {
  >     echo $1 > $1
  >     hg ci -m $1 -d "$2 0"
  > }

  $ initrepo ()
  > {
  >     hg init $1
  >     cd $1
  >     for x in a b c d e f ; do
  >         echo $x$x$x$x$x > $x
  >         hg add $x
  >     done
  >     hg ci -m 'Initial commit'
  >     modwithdate a 1
  >     modwithdate b 2
  >     modwithdate c 3
  >     modwithdate d 4
  >     modwithdate e 5
  >     modwithdate f 6
  >     echo 'I can haz no commute' > e
  >     hg ci -m 'does not commute with e' -d '7 0'
  >     cd ..
  > }

  $ initrepo r
  $ cd r
Initial generation of the command files

  $ EDITED="$TESTTMP/editedhistory"
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 3 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 4 >> $EDITED
  $ hg log --template 'fold {node|short} {rev} {desc}\n' -r 7 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 5 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 6 >> $EDITED
  $ cat $EDITED
  pick 092e4ce14829 3 c
  pick ae78f4c9d74f 4 d
  fold 42abbb61bede 7 does not commute with e
  pick 7f3755409b00 5 e
  pick dd184f2faeb0 6 f

log before edit
  $ hg log --graph
  @  changeset:   7:42abbb61bede
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:07 1970 +0000
  |  summary:     does not commute with e
  |
  o  changeset:   6:dd184f2faeb0
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   5:7f3755409b00
  |  user:        test
  |  date:        Thu Jan 01 00:00:05 1970 +0000
  |  summary:     e
  |
  o  changeset:   4:ae78f4c9d74f
  |  user:        test
  |  date:        Thu Jan 01 00:00:04 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 1970 +0000
  |  summary:     a
  |
  o  changeset:   0:1715188a53c7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     Initial commit
  

edit the history
  $ hg histedit 3 --commands $EDITED 2>&1 | fixbundle
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (fold 42abbb61bede)
  (hg histedit --continue to resume)

fix up
  $ echo 'I can haz no commute' > e
  $ hg resolve --mark e
  (no more unresolved files)
  continue: hg histedit --continue
  $ HGEDITOR=cat hg histedit --continue 2>&1 | fixbundle | grep -v '2 files removed'
  d
  ***
  does not commute with e
  
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: changed d
  HG: changed e
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (pick 7f3755409b00)
  (hg histedit --continue to resume)

just continue this time
keep the non-commuting change, and thus the pending change will be dropped
  $ hg revert -r 'p1()' e
  $ hg resolve --mark e
  (no more unresolved files)
  continue: hg histedit --continue
  $ hg diff
  $ hg histedit --continue 2>&1 | fixbundle
  7f3755409b00: skipping changeset (no changes)

log after edit
  $ hg log --graph
  @  changeset:   5:1300355b1a54
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   4:e2ac33269083
  |  user:        test
  |  date:        Thu Jan 01 00:00:07 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 1970 +0000
  |  summary:     a
  |
  o  changeset:   0:1715188a53c7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     Initial commit
  

contents of e
  $ hg cat e
  I can haz no commute

manifest
  $ hg manifest
  a
  b
  c
  d
  e
  f

  $ cd ..

Repeat test using "roll", not "fold". "roll" folds in changes but drops message and date

  $ initrepo r2
  $ cd r2

Initial generation of the command files

  $ EDITED="$TESTTMP/editedhistory.2"
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 3 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 4 >> $EDITED
  $ hg log --template 'roll {node|short} {rev} {desc}\n' -r 7 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 5 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 6 >> $EDITED
  $ cat $EDITED
  pick 092e4ce14829 3 c
  pick ae78f4c9d74f 4 d
  roll 42abbb61bede 7 does not commute with e
  pick 7f3755409b00 5 e
  pick dd184f2faeb0 6 f

log before edit
  $ hg log --graph
  @  changeset:   7:42abbb61bede
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:07 1970 +0000
  |  summary:     does not commute with e
  |
  o  changeset:   6:dd184f2faeb0
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   5:7f3755409b00
  |  user:        test
  |  date:        Thu Jan 01 00:00:05 1970 +0000
  |  summary:     e
  |
  o  changeset:   4:ae78f4c9d74f
  |  user:        test
  |  date:        Thu Jan 01 00:00:04 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 1970 +0000
  |  summary:     a
  |
  o  changeset:   0:1715188a53c7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     Initial commit
  

edit the history
  $ hg histedit 3 --commands $EDITED 2>&1 | fixbundle
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (roll 42abbb61bede)
  (hg histedit --continue to resume)

fix up
  $ echo 'I can haz no commute' > e
  $ hg resolve --mark e
  (no more unresolved files)
  continue: hg histedit --continue
  $ hg histedit --continue 2>&1 | fixbundle | grep -v '2 files removed'
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (pick 7f3755409b00)
  (hg histedit --continue to resume)

just continue this time
  $ hg revert -r 'p1()' e
  $ hg resolve --mark e
  (no more unresolved files)
  continue: hg histedit --continue
  $ hg histedit --continue 2>&1 | fixbundle
  7f3755409b00: skipping changeset (no changes)

log after edit
  $ hg log --graph
  @  changeset:   5:b538bcb461be
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   4:317e37cb6d66
  |  user:        test
  |  date:        Thu Jan 01 00:00:04 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 1970 +0000
  |  summary:     a
  |
  o  changeset:   0:1715188a53c7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     Initial commit
  

contents of e
  $ hg cat e
  I can haz no commute

manifest
  $ hg manifest
  a
  b
  c
  d
  e
  f

description is taken from rollup target commit

  $ hg log --debug --rev 4
  changeset:   4:317e37cb6d66c1c84628c00e5bf4c8c292831951
  phase:       draft
  parent:      3:092e4ce14829f4974399ce4316d59f64ef0b6725
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    4:b068a323d969f22af1296ec6a5ea9384cef437ac
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  files:       d e
  extra:       branch=default
  extra:       histedit_source=ae78f4c9d74ffa4b6cb5045001c303fe9204e890,42abbb61bede6f4366fa1e74a664343e5d558a70
  description:
  d
  
  

done with repo r2

  $ cd ..