$ cat > nlinks.py <<EOF

  > import os, sys

  > for f in sorted(sys.stdin.readlines()):

  >     f = f[:-1]

  >     print os.lstat(f).st_nlink, f

  > EOF

  $ nlinksdir()

  > {

  >     find $1 -type f | python $TESTTMP/nlinks.py

  > }

Some implementations of cp can't create hardlinks (replaces 'cp -al' on Linux):

  $ cat > linkcp.py <<EOF

  > from mercurial import util

  > import sys

  > util.copyfiles(sys.argv[1], sys.argv[2], hardlink=True)

  > EOF

  $ linkcp()

  > {

  >     python $TESTTMP/linkcp.py $1 $2

  > }

Prepare repo r1:

  $ mkdir r1

  $ cd r1

  $ hg init

  $ echo c1 > f1

  $ hg add f1

  $ hg ci -m0

  $ mkdir d1

  $ cd d1

  $ echo c2 > f2

  $ hg add f2

  $ hg ci -m1

  $ cd ../..

  $ nlinksdir r1/.hg/store

  1 r1/.hg/store/00changelog.i

  1 r1/.hg/store/00manifest.i

  1 r1/.hg/store/data/d1/f2.i

  1 r1/.hg/store/data/f1.i

  1 r1/.hg/store/fncache

  1 r1/.hg/store/undo

Create hardlinked clone r2:

  $ hg clone -U --debug r1 r2

  linked 7 files

Create non-hardlinked clone r3:

  $ hg clone --pull r1 r3

  requesting all changes

  adding changesets

  adding manifests

  adding file changes

  added 2 changesets with 2 changes to 2 files

  updating to branch default

  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

Repos r1 and r2 should now contain hardlinked files:

  $ nlinksdir r1/.hg/store

  2 r1/.hg/store/00changelog.i

  2 r1/.hg/store/00manifest.i

  2 r1/.hg/store/data/d1/f2.i

  2 r1/.hg/store/data/f1.i

  2 r1/.hg/store/fncache

  1 r1/.hg/store/undo

  $ nlinksdir r2/.hg/store

  2 r2/.hg/store/00changelog.i

  2 r2/.hg/store/00manifest.i

  2 r2/.hg/store/data/d1/f2.i

  2 r2/.hg/store/data/f1.i

  2 r2/.hg/store/fncache

Repo r3 should not be hardlinked:

  $ nlinksdir r3/.hg/store

  1 r3/.hg/store/00changelog.i

  1 r3/.hg/store/00manifest.i

  1 r3/.hg/store/data/d1/f2.i

  1 r3/.hg/store/data/f1.i

  1 r3/.hg/store/fncache

  1 r3/.hg/store/undo

Create a non-inlined filelog in r3:

  $ cd r3/d1

  $ python -c 'for x in range(10000): print x' >> data1

  $ for j in 0 1 2 3 4 5 6 7 8 9; do

  >   cat data1 >> f2

  >   hg commit -m$j

  > done

  $ cd ../..

  $ nlinksdir r3/.hg/store

  1 r3/.hg/store/00changelog.i

  1 r3/.hg/store/00manifest.i

  1 r3/.hg/store/data/d1/f2.d

  1 r3/.hg/store/data/d1/f2.i

  1 r3/.hg/store/data/f1.i

  1 r3/.hg/store/fncache

  1 r3/.hg/store/undo

Push to repo r1 should break up most hardlinks in r2:

  $ hg -R r2 verify

  checking changesets

  checking manifests

  crosschecking files in changesets and manifests

  checking files

  2 files, 2 changesets, 2 total revisions

  $ cd r3

  $ hg push

  pushing to $TESTTMP/r1

  searching for changes

  adding changesets

  adding manifests

  adding file changes

  added 10 changesets with 10 changes to 1 files

  $ cd ..

  $ nlinksdir r2/.hg/store

  1 r2/.hg/store/00changelog.i

  1 r2/.hg/store/00manifest.i

  1 r2/.hg/store/data/d1/f2.i

  2 r2/.hg/store/data/f1.i

  1 r2/.hg/store/fncache

  $ hg -R r2 verify

  checking changesets

  checking manifests

  crosschecking files in changesets and manifests

  checking files

  2 files, 2 changesets, 2 total revisions

  $ cd r1

  $ hg up

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

Committing a change to f1 in r1 must break up hardlink f1.i in r2:

  $ echo c1c1 >> f1

  $ hg ci -m00

  $ cd ..

  $ nlinksdir r2/.hg/store

  1 r2/.hg/store/00changelog.i

  1 r2/.hg/store/00manifest.i

  1 r2/.hg/store/data/d1/f2.i

  1 r2/.hg/store/data/f1.i

  1 r2/.hg/store/fncache

  $ cd r3

  $ hg tip --template '{rev}:{node|short}\n'

  11:a6451b6bc41f

  $ echo bla > f1

  $ hg ci -m1

  $ cd ..

Create hardlinked copy r4 of r3 (on Linux, we would call 'cp -al'):

  $ linkcp r3 r4

r4 has hardlinks in the working dir (not just inside .hg):

  $ nlinksdir r4

  2 r4/.hg/00changelog.i

  2 r4/.hg/branch

  2 r4/.hg/branchheads.cache

  2 r4/.hg/dirstate

  2 r4/.hg/hgrc

  2 r4/.hg/last-message.txt

  2 r4/.hg/requires

  2 r4/.hg/store/00changelog.i

  2 r4/.hg/store/00manifest.i

  2 r4/.hg/store/data/d1/f2.d

  2 r4/.hg/store/data/d1/f2.i

  2 r4/.hg/store/data/f1.i

  2 r4/.hg/store/fncache

  2 r4/.hg/store/undo

  2 r4/.hg/tags.cache

  2 r4/.hg/undo.branch

  2 r4/.hg/undo.desc

  2 r4/.hg/undo.dirstate

  2 r4/d1/data1

  2 r4/d1/f2

  2 r4/f1

Update back to revision 11 in r4 should break hardlink of file f1:

  $ hg -R r4 up 11

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

  $ nlinksdir r4

  2 r4/.hg/00changelog.i

  1 r4/.hg/branch

  2 r4/.hg/branchheads.cache

  1 r4/.hg/dirstate

  2 r4/.hg/hgrc

  2 r4/.hg/last-message.txt

  2 r4/.hg/requires

  2 r4/.hg/store/00changelog.i

  2 r4/.hg/store/00manifest.i

  2 r4/.hg/store/data/d1/f2.d

  2 r4/.hg/store/data/d1/f2.i

  2 r4/.hg/store/data/f1.i

  2 r4/.hg/store/fncache

  2 r4/.hg/store/undo

  2 r4/.hg/tags.cache

  2 r4/.hg/undo.branch

  2 r4/.hg/undo.desc

  2 r4/.hg/undo.dirstate

  2 r4/d1/data1

  2 r4/d1/f2

  1 r4/f1

Test hardlinking outside hg:

  $ mkdir x

  $ echo foo > x/a

  $ linkcp x y

  $ echo bar >> y/a

No diff if hardlink:

  $ diff x/a y/a

Test mq hardlinking:

  $ echo "[extensions]" >> $HGRCPATH

  $ echo "mq=" >> $HGRCPATH

  $ hg init a

  $ cd a

  $ hg qimport -n foo - << EOF

  > # HG changeset patch

  > # Date 1 0

  > diff -r 2588a8b53d66 a

  > --- /dev/null	Thu Jan 01 00:00:00 1970 +0000

  > +++ b/a	Wed Jul 23 15:54:29 2008 +0200

  > @@ -0,0 +1,1 @@

  > +a

  > EOF

  adding foo to series file

  $ hg qpush

  applying foo

  now at: foo

  $ cd ..

  $ linkcp a b

  $ cd b

  $ hg qimport -n bar - << EOF

  > # HG changeset patch

  > # Date 2 0

  > diff -r 2588a8b53d66 a

  > --- /dev/null	Thu Jan 01 00:00:00 1970 +0000

  > +++ b/b	Wed Jul 23 15:54:29 2008 +0200

  > @@ -0,0 +1,1 @@

  > +b

  > EOF

  adding bar to series file

  $ hg qpush

  applying bar

  now at: bar

  $ cat .hg/patches/status

  430ed4828a74fa4047bc816a25500f7472ab4bfe:foo

  4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c:bar

  $ cat .hg/patches/series

  foo

  bar

  $ cat ../a/.hg/patches/status

  430ed4828a74fa4047bc816a25500f7472ab4bfe:foo

  $ cat ../a/.hg/patches/series

  foo

Test tags hardlinking:

  $ hg qdel -r qbase:qtip

  patch foo finalized without changeset message

  patch bar finalized without changeset message

  $ hg tag -l lfoo

  $ hg tag foo

  $ cd ..

  $ linkcp b c

  $ cd c

  $ hg tag -l -r 0 lbar

  $ hg tag -r 0 bar

  $ cat .hgtags

  4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c foo

  430ed4828a74fa4047bc816a25500f7472ab4bfe bar

  $ cat .hg/localtags

  4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c lfoo

  430ed4828a74fa4047bc816a25500f7472ab4bfe lbar

  $ cat ../b/.hgtags

  4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c foo

  $ cat ../b/.hg/localtags

  4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c lfoo