tests/test-narrow-acl.t

localrepo: stop doing special dirstate backup at transaction open

Since the dirstate writes are already managed by the transaction, we already do
a backup of the dirstate when necessary (and even trigger one to keep `hg
rollback` happy).

We needs some special code to deal with the initial empty checkout, but it is
not too complicated.

Managing variable filename (as dirstate-v2 uses) at the "journalfile" level, is
complex and fragile (which is consistent with the fact these files are not
journal…). If we no longer do it, our life is significantly simpler.

In some sense, we apply the xkcd-1134¹ solution to our savebackup/restorebackup
problem.

[1] https://xkcd.com/1134/

(the change to test-hardlink are expect as decreasing the number of duplicated
backup drive the hardlink count down)

Make a narrow clone then archive it
  $ . "$TESTDIR/narrow-library.sh"

  $ hg init master
  $ cd master

  $ for x in `$TESTDIR/seq.py 3`; do
  >   echo $x > "f$x"
  >   hg add "f$x"
  >   hg commit -m "Add $x"
  > done
  $ cat >> .hg/hgrc << EOF
  > [narrowacl]
  > default.includes=f1 f2
  > EOF
  $ hg serve -a localhost -p $HGPORT1 -d --pid-file=hg.pid
  $ cat hg.pid >> "$DAEMON_PIDS"

  $ cd ..
  $ hg clone http://localhost:$HGPORT1 narrowclone1
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 2 changes to 2 files
  new changesets * (glob)
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

The clone directory should only contain f1 and f2
  $ ls -A -1 narrowclone1 | sort
  .hg
  f1
  f2

Requirements should contain narrowhg
  $ hg debugrequires -R narrowclone1 | grep narrowhg
  narrowhg-experimental

NarrowHG should track f1 and f2
  $ hg -R narrowclone1 tracked
  I path:f1
  I path:f2

Narrow should not be able to widen to include f3
  $ hg -R narrowclone1 tracked --addinclude f3
  comparing with http://localhost:$HGPORT1/
  searching for changes
  abort: The following includes are not accessible for test: ['path:f3']
  [255]
  $ ls -A -1 narrowclone1 | sort
  .hg
  f1
  f2
  $ hg -R narrowclone1 tracked
  I path:f1
  I path:f2

Narrow should allow widen to include f2
  $ hg -R narrowclone1 tracked --removeinclude f2 > /dev/null
  $ hg -R narrowclone1 tracked
  I path:f1
  $ ls -A -1 narrowclone1 | sort
  .hg
  f1
  $ hg -R narrowclone1 tracked --addinclude f2
  comparing with http://localhost:$HGPORT1/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 0 changesets with 1 changes to 1 files
  $ hg -R narrowclone1 tracked
  I path:f1
  I path:f2
  $ ls -A -1 narrowclone1 | sort
  .hg
  f1
  f2