view tests/test-win32text.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outdated and unsupported repo format.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
  $ cat > unix2dos.py <<EOF
  > import sys
  > 
  > for path in sys.argv[1:]:
  >     data = file(path, 'rb').read()
  >     data = data.replace('\n', '\r\n')
  >     file(path, 'wb').write(data)
  > EOF
  $ echo '[hooks]' >> .hg/hgrc
  $ echo 'pretxncommit.crlf = python:hgext.win32text.forbidcrlf' >> .hg/hgrc
  $ echo 'pretxnchangegroup.crlf = python:hgext.win32text.forbidcrlf' >> .hg/hgrc
  $ cat .hg/hgrc
  [hooks]
  pretxncommit.crlf = python:hgext.win32text.forbidcrlf
  pretxnchangegroup.crlf = python:hgext.win32text.forbidcrlf

  $ echo hello > f
  $ hg add f

commit should succeed

  $ hg ci -m 1

  $ hg clone . ../zoz
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cp .hg/hgrc ../zoz/.hg
  $ python unix2dos.py f

commit should fail

  $ hg ci -m 2.1
  attempt to commit or push text file(s) using CRLF line endings
  in f583ea08d42a: f
  transaction abort!
  rollback completed
  abort: pretxncommit.crlf hook failed
  [255]

  $ mv .hg/hgrc .hg/hgrc.bak

commits should succeed

  $ hg ci -m 2
  $ hg cp f g
  $ hg ci -m 2.2

push should fail

  $ hg push ../zoz
  pushing to ../zoz
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files
  attempt to commit or push text file(s) using CRLF line endings
  in bc2d09796734: g
  in b1aa5cde7ff4: f
  
  To prevent this mistake in your local repository,
  add to Mercurial.ini or .hg/hgrc:
  
  [hooks]
  pretxncommit.crlf = python:hgext.win32text.forbidcrlf
  
  and also consider adding:
  
  [extensions]
  win32text =
  [encode]
  ** = cleverencode:
  [decode]
  ** = cleverdecode:
  transaction abort!
  rollback completed
  abort: pretxnchangegroup.crlf hook failed
  [255]

  $ mv .hg/hgrc.bak .hg/hgrc
  $ echo hello > f
  $ hg rm g

commit should succeed

  $ hg ci -m 2.3

push should succeed

  $ hg push ../zoz
  pushing to ../zoz
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 2 files

and now for something completely different

  $ mkdir d
  $ echo hello > d/f2
  $ python unix2dos.py d/f2
  $ hg add d/f2
  $ hg ci -m 3
  attempt to commit or push text file(s) using CRLF line endings
  in 053ba1a3035a: d/f2
  transaction abort!
  rollback completed
  abort: pretxncommit.crlf hook failed
  [255]
  $ hg revert -a
  forgetting d/f2 (glob)
  $ rm d/f2

  $ hg rem f
  $ hg ci -m 4

  $ $PYTHON -c 'file("bin", "wb").write("hello\x00\x0D\x0A")'
  $ hg add bin
  $ hg ci -m 5
  $ hg log -v
  changeset:   5:f0b1c8d75fce
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       bin
  description:
  5
  
  
  changeset:   4:77796dbcd4ad
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  4
  
  
  changeset:   3:7c1b5430b350
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f g
  description:
  2.3
  
  
  changeset:   2:bc2d09796734
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       g
  description:
  2.2
  
  
  changeset:   1:b1aa5cde7ff4
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  2
  
  
  changeset:   0:fcf06d5c4e1d
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  1
  
  
  $ hg clone . dupe
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ for x in a b c d; do echo content > dupe/$x; done
  $ hg -R dupe add
  adding dupe/a (glob)
  adding dupe/b (glob)
  adding dupe/c (glob)
  adding dupe/d (glob)
  $ python unix2dos.py dupe/b dupe/c dupe/d
  $ hg -R dupe ci -m a dupe/a
  $ hg -R dupe ci -m b/c dupe/[bc]
  $ hg -R dupe ci -m d dupe/d
  $ hg -R dupe log -v
  changeset:   8:67ac5962ab43
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       d
  description:
  d
  
  
  changeset:   7:68c127d1834e
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       b c
  description:
  b/c
  
  
  changeset:   6:adbf8bf7f31d
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       a
  description:
  a
  
  
  changeset:   5:f0b1c8d75fce
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       bin
  description:
  5
  
  
  changeset:   4:77796dbcd4ad
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  4
  
  
  changeset:   3:7c1b5430b350
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f g
  description:
  2.3
  
  
  changeset:   2:bc2d09796734
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       g
  description:
  2.2
  
  
  changeset:   1:b1aa5cde7ff4
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  2
  
  
  changeset:   0:fcf06d5c4e1d
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  1
  
  
  $ hg pull dupe
  pulling from dupe
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 4 changes to 4 files
  attempt to commit or push text file(s) using CRLF line endings
  in 67ac5962ab43: d
  in 68c127d1834e: b
  in 68c127d1834e: c
  
  To prevent this mistake in your local repository,
  add to Mercurial.ini or .hg/hgrc:
  
  [hooks]
  pretxncommit.crlf = python:hgext.win32text.forbidcrlf
  
  and also consider adding:
  
  [extensions]
  win32text =
  [encode]
  ** = cleverencode:
  [decode]
  ** = cleverdecode:
  transaction abort!
  rollback completed
  abort: pretxnchangegroup.crlf hook failed
  [255]

  $ hg log -v
  changeset:   5:f0b1c8d75fce
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       bin
  description:
  5
  
  
  changeset:   4:77796dbcd4ad
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  4
  
  
  changeset:   3:7c1b5430b350
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f g
  description:
  2.3
  
  
  changeset:   2:bc2d09796734
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       g
  description:
  2.2
  
  
  changeset:   1:b1aa5cde7ff4
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  2
  
  
  changeset:   0:fcf06d5c4e1d
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  1
  
  
  $ rm .hg/hgrc
  $ (echo some; echo text) > f3
  $ $PYTHON -c 'file("f4.bat", "wb").write("rem empty\x0D\x0A")'
  $ hg add f3 f4.bat
  $ hg ci -m 6
  $ cat bin
  hello\x00\r (esc)
  $ cat f3
  some
  text
  $ cat f4.bat
  rem empty\r (esc)

  $ echo '[extensions]' >> .hg/hgrc
  $ echo 'win32text = ' >> .hg/hgrc
  $ echo '[decode]' >> .hg/hgrc
  $ echo '** = cleverdecode:' >> .hg/hgrc
  $ echo '[encode]' >> .hg/hgrc
  $ echo '** = cleverencode:' >> .hg/hgrc
  $ cat .hg/hgrc
  [extensions]
  win32text = 
  [decode]
  ** = cleverdecode:
  [encode]
  ** = cleverencode:

Trigger deprecation warning:

  $ hg id -t
  win32text is deprecated: https://mercurial-scm.org/wiki/Win32TextExtension
  tip

Disable warning:

  $ echo '[win32text]' >> .hg/hgrc
  $ echo 'warn = no' >> .hg/hgrc
  $ hg id -t
  tip

  $ rm f3 f4.bat bin
  $ hg co -C
  WARNING: f4.bat already has CRLF line endings
  and does not need EOL conversion by the win32text plugin.
  Before your next commit, please reconsider your encode/decode settings in 
  Mercurial.ini or $TESTTMP/t/.hg/hgrc. (glob)
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat bin
  hello\x00\r (esc)
  $ cat f3
  some\r (esc)
  text\r (esc)
  $ cat f4.bat
  rem empty\r (esc)

  $ $PYTHON -c 'file("f5.sh", "wb").write("# empty\x0D\x0A")'
  $ hg add f5.sh
  $ hg ci -m 7
  $ cat f5.sh
  # empty\r (esc)
  $ hg cat f5.sh
  # empty
  $ echo '% just linefeed' > linefeed
  $ hg ci -qAm 8 linefeed
  $ cat linefeed
  % just linefeed
  $ hg cat linefeed
  % just linefeed
  $ hg st -q
  $ hg revert -a linefeed
  no changes needed to linefeed
  $ cat linefeed
  % just linefeed
  $ hg st -q
  $ echo modified >> linefeed
  $ hg st -q
  M linefeed
  $ hg revert -a
  reverting linefeed
  $ hg st -q
  $ cat linefeed
  % just linefeed\r (esc)

  $ cd ..