tests/test-permissions.t

nodemap: introduce append-only incremental update of the persistent data

Rewriting the full nodemap for each transaction has a cost we would like to
avoid. We introduce a new way to write persistent nodemap data by adding new
information at the end for file. Any new and updated block as added at the end
of the file. The last block is the new root node.

With this method, some of the block already on disk get "dereferenced" and
become dead data. In later changesets, We'll start tracking the amount of dead
data to eventually re-generate a full nodemap.

Differential Revision: https://phab.mercurial-scm.org/D7886

#require unix-permissions no-root reporevlogstore

  $ hg init t
  $ cd t

  $ echo foo > a
  $ hg add a

  $ hg commit -m "1"

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 1 changes to 1 files

  $ chmod -r .hg/store/data/a.i

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  abort: Permission denied: '$TESTTMP/t/.hg/store/data/a.i'
  [255]

  $ chmod +r .hg/store/data/a.i

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 1 changes to 1 files

  $ chmod -w .hg/store/data/a.i

  $ echo barber > a
  $ hg commit -m "2"
  trouble committing a!
  abort: Permission denied: '$TESTTMP/t/.hg/store/data/a.i'
  [255]

  $ chmod -w .

  $ hg diff --nodates
  diff -r 2a18120dc1c9 a
  --- a/a
  +++ b/a
  @@ -1,1 +1,1 @@
  -foo
  +barber

  $ chmod +w .

  $ chmod +w .hg/store/data/a.i
  $ mkdir dir
  $ touch dir/a
  $ hg status
  M a
  ? dir/a
  $ chmod -rx dir

#if no-fsmonitor

(fsmonitor makes "hg status" avoid accessing to "dir")

  $ hg status
  dir: Permission denied
  M a

#endif

Reenable perm to allow deletion:

  $ chmod +rx dir

  $ cd ..