tests/test-remote-hidden.t

rust: fix unsound `OwningDirstateMap`

As per the previous patch, `OwningDirstateMap` is unsound. Self-referential
structs are difficult to implement correctly in Rust since the compiler is
free to move structs around as much as it wants to. They are also very rarely
needed in practice, so the state-of-the-art on how they should be done within
the Rust rules is still a bit new.

The crate `ouroboros` is an attempt at providing a safe way (in the Rust sense)
of declaring self-referential structs. It is getting a lot attention and was
improved very quickly when soundness issues were found in the past: rather than
relying on our own (limited) review circle, we might as well use the de-facto
common crate to fix this problem. This will give us a much better chance of
finding issues should any new ones be discovered as well as the benefit of
fewer `unsafe` APIs of our own.

I was starting to think about how I would present a safe API to the old struct
but soon realized that the callback-based approach was already done in
`ouroboros`, along with a lot more care towards refusing incorrect structs.

In short: we don't return a mutable reference to the `DirstateMap` anymore, we
expect users of its API to pass a `FnOnce` that takes the map as an argument.
This allows our `OwningDirstateMap` to control the input and output lifetimes
of the code that modifies it to prevent such issues.

Changing to `ouroboros` meant changing every API with it, but it is relatively
low churn in the end. It correctly identified the example buggy modification of
`copy_map_insert` outlined in the previous patch as violating the borrow rules.

Differential Revision: https://phab.mercurial-scm.org/D12429

========================================================
Test the ability to access a hidden revision on a server
========================================================

#require serve

  $ . $TESTDIR/testlib/obsmarker-common.sh
  $ cat >> $HGRCPATH << EOF
  > [phases]
  > # public changeset are not obsolete
  > publish=false
  > [experimental]
  > evolution=all
  > [ui]
  > logtemplate='{rev}:{node|short} {desc} [{phase}]\n'
  > EOF

Setup a simple repository with some hidden revisions
----------------------------------------------------

Testing the `served.hidden` view

  $ hg init repo-with-hidden
  $ cd repo-with-hidden

  $ echo 0 > a
  $ hg ci -qAm "c_Public"
  $ hg phase --public
  $ echo 1 > a
  $ hg ci -m "c_Amend_Old"
  $ echo 2 > a
  $ hg ci -m "c_Amend_New" --amend
  $ hg up ".^"
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo 3 > a
  $ hg ci -m "c_Pruned"
  created new head
  $ hg debugobsolete --record-parents `getid 'desc("c_Pruned")'` -d '0 0'
  1 new obsolescence markers
  obsoleted 1 changesets
  $ hg up ".^"
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo 4 > a
  $ hg ci -m "c_Secret" --secret
  created new head
  $ echo 5 > a
  $ hg ci -m "c_Secret_Pruned" --secret
  $ hg debugobsolete --record-parents `getid 'desc("c_Secret_Pruned")'` -d '0 0'
  1 new obsolescence markers
  obsoleted 1 changesets
  $ hg up null
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ hg log -G -T '{rev}:{node|short} {desc} [{phase}]\n' --hidden
  x  5:8d28cbe335f3 c_Secret_Pruned [secret]
  |
  o  4:1c6afd79eb66 c_Secret [secret]
  |
  | x  3:5d1575e42c25 c_Pruned [draft]
  |/
  | o  2:c33affeb3f6b c_Amend_New [draft]
  |/
  | x  1:be215fbb8c50 c_Amend_Old [draft]
  |/
  o  0:5f354f46e585 c_Public [public]
  
  $ hg debugobsolete
  be215fbb8c5090028b00154c1fe877ad1b376c61 c33affeb3f6b4e9621d1839d6175ddc07708807c 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '9', 'operation': 'amend', 'user': 'test'}
  5d1575e42c25b7f2db75cd4e0b881b1c35158fae 0 {5f354f46e5853535841ec7a128423e991ca4d59b} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
  8d28cbe335f311bc89332d7bbe8a07889b6914a0 0 {1c6afd79eb6663275bbe30097e162b1c24ced0f0} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}

  $ cd ..

Test the feature
================

Check cache pre-warm
--------------------

  $ ls -1 repo-with-hidden/.hg/cache
  branch2
  branch2-base
  branch2-served
  branch2-served.hidden
  branch2-visible
  rbc-names-v1
  rbc-revs-v1
  tags2
  tags2-visible

Check that the `served.hidden` repoview
---------------------------------------

  $ hg -R repo-with-hidden serve -p $HGPORT -d --pid-file hg.pid --config web.view=served.hidden
  $ cat hg.pid >> $DAEMON_PIDS

changesets in secret and higher phases are not visible through hgweb

  $ hg -R repo-with-hidden log --template "revision:    {rev}\\n" --rev "reverse(not secret())"
  revision:    2
  revision:    0
  $ hg -R repo-with-hidden log --template "revision:    {rev}\\n" --rev "reverse(not secret())" --hidden
  revision:    3
  revision:    2
  revision:    1
  revision:    0
  $ get-with-headers.py localhost:$HGPORT 'log?style=raw' | grep revision:
  revision:    3
  revision:    2
  revision:    1
  revision:    0

  $ killdaemons.py