$ 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

  > }

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