tests/test-rhg.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

#require rhg

  $ NO_FALLBACK="env RHG_ON_UNSUPPORTED=abort"

Unimplemented command
  $ $NO_FALLBACK rhg unimplemented-command
  unsupported feature: error: Found argument 'unimplemented-command' which wasn't expected, or isn't valid in this context
  
  USAGE:
      rhg [OPTIONS] <SUBCOMMAND>
  
  For more information try --help
  
  [252]
  $ rhg unimplemented-command --config rhg.on-unsupported=abort-silent
  [252]

Finding root
  $ $NO_FALLBACK rhg root
  abort: no repository found in '$TESTTMP' (.hg not found)!
  [255]

  $ hg init repository
  $ cd repository
  $ $NO_FALLBACK rhg root
  $TESTTMP/repository

Reading and setting configuration
  $ echo "[ui]" >> $HGRCPATH
  $ echo "username = user1" >> $HGRCPATH
  $ $NO_FALLBACK rhg config ui.username
  user1
  $ echo "[ui]" >> .hg/hgrc
  $ echo "username = user2" >> .hg/hgrc
  $ $NO_FALLBACK rhg config ui.username
  user2
  $ $NO_FALLBACK rhg --config ui.username=user3 config ui.username
  user3

Unwritable file descriptor
  $ $NO_FALLBACK rhg root > /dev/full
  abort: No space left on device (os error 28)
  [255]

Deleted repository
  $ rm -rf `pwd`
  $ $NO_FALLBACK rhg root
  abort: error getting current working directory: $ENOENT$
  [255]

Listing tracked files
  $ cd $TESTTMP
  $ hg init repository
  $ cd repository
  $ for i in 1 2 3; do
  >   echo $i >> file$i
  >   hg add file$i
  > done
  > hg commit -m "commit $i" -q

Listing tracked files from root
  $ $NO_FALLBACK rhg files
  file1
  file2
  file3

Listing tracked files from subdirectory
  $ mkdir -p path/to/directory
  $ cd path/to/directory
  $ $NO_FALLBACK rhg files
  ../../../file1
  ../../../file2
  ../../../file3

Listing tracked files through broken pipe
  $ $NO_FALLBACK rhg files | head -n 1
  ../../../file1

Debuging data in inline index
  $ cd $TESTTMP
  $ rm -rf repository
  $ hg init repository
  $ cd repository
  $ for i in 1 2 3 4 5 6; do
  >   echo $i >> file-$i
  >   hg add file-$i
  >   hg commit -m "Commit $i" -q
  > done
  $ $NO_FALLBACK rhg debugdata -c 2
  8d0267cb034247ebfa5ee58ce59e22e57a492297
  test
  0 0
  file-3
  
  Commit 3 (no-eol)
  $ $NO_FALLBACK rhg debugdata -m 2
  file-1\x00b8e02f6433738021a065f94175c7cd23db5f05be (esc)
  file-2\x005d9299349fc01ddd25d0070d149b124d8f10411e (esc)
  file-3\x002661d26c649684b482d10f91960cc3db683c38b4 (esc)

Debuging with full node id
  $ $NO_FALLBACK rhg debugdata -c `hg log -r 0 -T '{node}'`
  d1d1c679d3053e8926061b6f45ca52009f011e3f
  test
  0 0
  file-1
  
  Commit 1 (no-eol)

Specifying revisions by changeset ID
  $ hg log -T '{node}\n'
  c6ad58c44207b6ff8a4fbbca7045a5edaa7e908b
  d654274993d0149eecc3cc03214f598320211900
  f646af7e96481d3a5470b695cf30ad8e3ab6c575
  cf8b83f14ead62b374b6e91a0e9303b85dfd9ed7
  91c6f6e73e39318534dc415ea4e8a09c99cd74d6
  6ae9681c6d30389694d8701faf24b583cf3ccafe
  $ $NO_FALLBACK rhg files -r cf8b83
  file-1
  file-2
  file-3
  $ $NO_FALLBACK rhg cat -r cf8b83 file-2
  2
  $ $NO_FALLBACK rhg cat --rev cf8b83 file-2
  2
  $ $NO_FALLBACK rhg cat -r c file-2
  abort: ambiguous revision identifier: c
  [255]
  $ $NO_FALLBACK rhg cat -r d file-2
  2
  $ $NO_FALLBACK rhg cat -r 0000 file-2
  file-2: no such file in rev 000000000000
  [1]

Cat files
  $ cd $TESTTMP
  $ rm -rf repository
  $ hg init repository
  $ cd repository
  $ echo "original content" > original
  $ hg add original
  $ hg commit -m "add original" original
Without `--rev`
  $ $NO_FALLBACK rhg cat original
  original content
With `--rev`
  $ $NO_FALLBACK rhg cat -r 0 original
  original content
Cat copied file should not display copy metadata
  $ hg copy original copy_of_original
  $ hg commit -m "add copy of original"
  $ $NO_FALLBACK rhg cat original
  original content
  $ $NO_FALLBACK rhg cat -r 1 copy_of_original
  original content


Fallback to Python
  $ $NO_FALLBACK rhg cat original --exclude="*.rs"
  unsupported feature: error: Found argument '--exclude' which wasn't expected, or isn't valid in this context
  
  USAGE:
      rhg cat [OPTIONS] <FILE>...
  
  For more information try --help
  
  [252]
  $ rhg cat original --exclude="*.rs"
  original content

  $ (unset RHG_FALLBACK_EXECUTABLE; rhg cat original --exclude="*.rs")
  abort: 'rhg.on-unsupported=fallback' without 'rhg.fallback-executable' set.
  [255]

  $ (unset RHG_FALLBACK_EXECUTABLE; rhg cat original)
  original content

  $ rhg cat original --exclude="*.rs" --config rhg.fallback-executable=false
  [1]

  $ rhg cat original --exclude="*.rs" --config rhg.fallback-executable=hg-non-existent
  tried to fall back to a 'hg-non-existent' sub-process but got error $ENOENT$
  unsupported feature: error: Found argument '--exclude' which wasn't expected, or isn't valid in this context
  
  USAGE:
      rhg cat [OPTIONS] <FILE>...
  
  For more information try --help
  
  [252]

  $ rhg cat original --exclude="*.rs" --config rhg.fallback-executable=rhg
  Blocking recursive fallback. The 'rhg.fallback-executable = rhg' config points to `rhg` itself.
  unsupported feature: error: Found argument '--exclude' which wasn't expected, or isn't valid in this context
  
  USAGE:
      rhg cat [OPTIONS] <FILE>...
  
  For more information try --help
  
  [252]

Fallback with shell path segments
  $ $NO_FALLBACK rhg cat .
  unsupported feature: `..` or `.` path segment
  [252]
  $ $NO_FALLBACK rhg cat ..
  unsupported feature: `..` or `.` path segment
  [252]
  $ $NO_FALLBACK rhg cat ../..
  unsupported feature: `..` or `.` path segment
  [252]

Fallback with filesets
  $ $NO_FALLBACK rhg cat "set:c or b"
  unsupported feature: fileset
  [252]

Fallback with generic hooks
  $ $NO_FALLBACK rhg cat original --config hooks.pre-cat=something
  unsupported feature: pre-cat hook defined
  [252]

  $ $NO_FALLBACK rhg cat original --config hooks.post-cat=something
  unsupported feature: post-cat hook defined
  [252]

  $ $NO_FALLBACK rhg cat original --config hooks.fail-cat=something
  unsupported feature: fail-cat hook defined
  [252]

Fallback with [defaults]
  $ $NO_FALLBACK rhg cat original --config "defaults.cat=-r null"
  unsupported feature: `defaults` config set
  [252]


Requirements
  $ $NO_FALLBACK rhg debugrequirements
  dotencode
  fncache
  generaldelta
  persistent-nodemap
  revlog-compression-zstd (zstd !)
  revlogv1
  share-safe
  sparserevlog
  store

  $ echo indoor-pool >> .hg/requires
  $ $NO_FALLBACK rhg files
  unsupported feature: repository requires feature unknown to this Mercurial: indoor-pool
  [252]

  $ $NO_FALLBACK rhg cat -r 1 copy_of_original
  unsupported feature: repository requires feature unknown to this Mercurial: indoor-pool
  [252]

  $ $NO_FALLBACK rhg debugrequirements
  unsupported feature: repository requires feature unknown to this Mercurial: indoor-pool
  [252]

  $ echo -e '\xFF' >> .hg/requires
  $ $NO_FALLBACK rhg debugrequirements
  abort: parse error in 'requires' file
  [255]

Persistent nodemap
  $ cd $TESTTMP
  $ rm -rf repository
  $ hg --config format.use-persistent-nodemap=no init repository
  $ cd repository
  $ $NO_FALLBACK rhg debugrequirements | grep nodemap
  [1]
  $ hg debugbuilddag .+5000 --overwritten-file --config "storage.revlog.nodemap.mode=warn"
  $ hg id -r tip
  c3ae8dec9fad tip
  $ ls .hg/store/00changelog*
  .hg/store/00changelog.d
  .hg/store/00changelog.i
  $ $NO_FALLBACK rhg files -r c3ae8dec9fad
  of

  $ cd $TESTTMP
  $ rm -rf repository
  $ hg --config format.use-persistent-nodemap=True init repository
  $ cd repository
  $ $NO_FALLBACK rhg debugrequirements | grep nodemap
  persistent-nodemap
  $ hg debugbuilddag .+5000 --overwritten-file --config "storage.revlog.nodemap.mode=warn"
  $ hg id -r tip
  c3ae8dec9fad tip
  $ ls .hg/store/00changelog*
  .hg/store/00changelog-*.nd (glob)
  .hg/store/00changelog.d
  .hg/store/00changelog.i
  .hg/store/00changelog.n

Specifying revisions by changeset ID
  $ $NO_FALLBACK rhg files -r c3ae8dec9fad
  of
  $ $NO_FALLBACK rhg cat -r c3ae8dec9fad of
  r5000

Crate a shared repository

  $ echo "[extensions]"      >> $HGRCPATH
  $ echo "share = "          >> $HGRCPATH

  $ cd $TESTTMP
  $ hg init repo1
  $ echo a > repo1/a
  $ hg -R repo1 commit -A -m'init'
  adding a

  $ hg share repo1 repo2
  updating working directory
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

And check that basic rhg commands work with sharing

  $ $NO_FALLBACK rhg files -R repo2
  repo2/a
  $ $NO_FALLBACK rhg -R repo2 cat -r 0 repo2/a
  a

Same with relative sharing

  $ hg share repo2 repo3 --relative
  updating working directory
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ $NO_FALLBACK rhg files -R repo3
  repo3/a
  $ $NO_FALLBACK rhg -R repo3 cat -r 0 repo3/a
  a

Same with share-safe

  $ echo "[format]"         >> $HGRCPATH
  $ echo "use-share-safe = True" >> $HGRCPATH

  $ cd $TESTTMP
  $ hg init repo4
  $ cd repo4
  $ echo a > a
  $ hg commit -A -m'init'
  adding a

  $ cd ..
  $ hg share repo4 repo5
  updating working directory
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

And check that basic rhg commands work with sharing

  $ cd repo5
  $ $NO_FALLBACK rhg files
  a
  $ $NO_FALLBACK rhg cat -r 0 a
  a

The blackbox extension is supported

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "blackbox =" >> $HGRCPATH
  $ echo "[blackbox]" >> $HGRCPATH
  $ echo "maxsize = 1" >> $HGRCPATH
  $ $NO_FALLBACK rhg files > /dev/null
  $ cat .hg/blackbox.log
  ????-??-?? ??:??:??.??? * @d3873e73d99ef67873dac33fbcc66268d5d2b6f4 (*)> (rust) files exited 0 after 0.??? seconds (glob)
  $ cat .hg/blackbox.log.1
  ????-??-?? ??:??:??.??? * @d3873e73d99ef67873dac33fbcc66268d5d2b6f4 (*)> (rust) files (glob)

Subrepos are not supported

  $ touch .hgsub
  $ $NO_FALLBACK rhg files
  unsupported feature: subrepos (.hgsub is present)
  [252]
  $ rhg files
  a
  $ rm .hgsub

The `:required` extension suboptions are correctly ignored

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "blackbox:required = yes" >> $HGRCPATH
  $ rhg files
  a
  $ echo "*:required = yes" >> $HGRCPATH
  $ rhg files
  a