$ 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

  $ cat > print.py <<EOF

  > import sys

  > print(sys.stdin.read().replace('\n', '<LF>').replace('\r', '<CR>').replace('\0', '<NUL>'))

  > 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

  $ echo hello > f

  $ hg add f

commit should succeed

  $ hg ci -m 1

  $ echo

  $ 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]

  $ echo

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

commits should succeed

  $ hg ci -m 2

  $ hg cp f g

  $ hg ci -m 2.2

  $ echo

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]

  $ echo

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

  $ echo hello > f

  $ hg rm g

commit should succeed

  $ hg ci -m 2.3

  $ echo

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

  $ echo

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

  $ rm d/f2

  $ echo

  $ hg rem f

  $ hg ci -m 4

  $ echo

  $ 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

  $ echo

  $ hg clone . dupe

  updating to branch default

  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ echo

  $ for x in a b c d; do echo content > dupe/$x; done

  $ hg -R dupe add

  adding dupe/a

  adding dupe/b

  adding dupe/c

  adding dupe/d

  $ 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

  $ echo

  $ 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]

  $ echo

  $ 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

  $ echo

  $ 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

  $ python print.py < bin

  hello<NUL><CR><LF>

  $ python print.py < f3

  some<LF>text<LF>

  $ python print.py < f4.bat

  rem empty<CR><LF>

  $ echo

  $ 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]