Init repo1:

  $ hg init repo1
  $ cd repo1
  $ echo "some text" > a
  $ hg add
  adding a
  $ hg ci -m first
  $ cat .hg/store/fncache
  data/a.i

Testing a.i/b:

  $ mkdir a.i
  $ echo "some other text" > a.i/b
  $ hg add
  adding a.i/b
  $ hg ci -m second
  $ cat .hg/store/fncache
  data/a.i
  data/a.i.hg/b.i

Testing a.i.hg/c:

  $ mkdir a.i.hg
  $ echo "yet another text" > a.i.hg/c
  $ hg add
  adding a.i.hg/c
  $ hg ci -m third
  $ cat .hg/store/fncache
  data/a.i
  data/a.i.hg/b.i
  data/a.i.hg.hg/c.i

Testing verify:

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  3 files, 3 changesets, 3 total revisions

  $ rm .hg/store/fncache

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
   data/a.i@0: missing revlog!
   data/a.i.hg/c.i@2: missing revlog!
   data/a.i/b.i@1: missing revlog!
  3 files, 3 changesets, 3 total revisions
  3 integrity errors encountered!
  (first damaged changeset appears to be 0)
  $ cd ..

Non store repo:

  $ hg --config format.usestore=False init foo
  $ cd foo
  $ mkdir tst.d
  $ echo foo > tst.d/foo
  $ hg ci -Amfoo
  adding tst.d/foo
  $ find .hg | sort
  .hg
  .hg/00changelog.i
  .hg/00manifest.i
  .hg/data
  .hg/data/tst.d.hg
  .hg/data/tst.d.hg/foo.i
  .hg/dirstate
  .hg/last-message.txt
  .hg/requires
  .hg/undo
  .hg/undo.branch
  .hg/undo.desc
  .hg/undo.dirstate
  $ cd ..

Non fncache repo:

  $ hg --config format.usefncache=False init bar
  $ cd bar
  $ mkdir tst.d
  $ echo foo > tst.d/Foo
  $ hg ci -Amfoo
  adding tst.d/Foo
  $ find .hg | sort
  .hg
  .hg/00changelog.i
  .hg/dirstate
  .hg/last-message.txt
  .hg/requires
  .hg/store
  .hg/store/00changelog.i
  .hg/store/00manifest.i
  .hg/store/data
  .hg/store/data/tst.d.hg
  .hg/store/data/tst.d.hg/_foo.i
  .hg/store/undo
  .hg/undo.branch
  .hg/undo.desc
  .hg/undo.dirstate
  $ cd ..