view tests/test-symlinks.t @ 49000:dd6b67d5c256 stable

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 symlink

#testcases dirstate-v1 dirstate-v2

#if dirstate-v2
  $ cat >> $HGRCPATH << EOF
  > [format]
  > use-dirstate-v2=1
  > [storage]
  > dirstate-v2.slow-path=allow
  > EOF
#endif

== tests added in 0.7 ==

  $ hg init test-symlinks-0.7; cd test-symlinks-0.7;
  $ touch foo; ln -s foo bar; ln -s nonexistent baz

import with add and addremove -- symlink walking should _not_ screwup.

  $ hg add
  adding bar
  adding baz
  adding foo
  $ hg forget bar baz foo
  $ hg addremove
  adding bar
  adding baz
  adding foo

commit -- the symlink should _not_ appear added to dir state

  $ hg commit -m 'initial'

  $ touch bomb

again, symlink should _not_ show up on dir state

  $ hg addremove
  adding bomb

Assert screamed here before, should go by without consequence

  $ hg commit -m 'is there a bug?'
  $ cd ..


== fifo & ignore ==

  $ hg init test; cd test;

  $ mkdir dir
  $ touch a.c dir/a.o dir/b.o

test what happens if we want to trick hg

  $ hg commit -A -m 0
  adding a.c
  adding dir/a.o
  adding dir/b.o
  $ echo "relglob:*.o" > .hgignore
  $ rm a.c
  $ rm dir/a.o
  $ rm dir/b.o
  $ mkdir dir/a.o
  $ ln -s nonexistent dir/b.o
  $ mkfifo a.c

it should show a.c, dir/a.o and dir/b.o deleted

  $ hg status
  M dir/b.o
  ! a.c
  ! dir/a.o
  ? .hgignore
  $ hg status a.c
  a.c: unsupported file type (type is fifo)
  ! a.c
  $ cd ..


== symlinks from outside the tree ==

test absolute path through symlink outside repo

  $ p=`pwd`
  $ hg init x
  $ ln -s x y
  $ cd x
  $ touch f
  $ hg add f
  $ hg status "$p"/y/f
  A f

try symlink outside repo to file inside

  $ ln -s x/f ../z

this should fail

  $ hg status ../z && { echo hg mistakenly exited with status 0; exit 1; } || :
  abort: ../z not under root '$TESTTMP/x'
  $ cd ..


== cloning symlinks ==
  $ hg init clone; cd clone;

try cloning symlink in a subdir
1. commit a symlink

  $ mkdir -p a/b/c
  $ cd a/b/c
  $ ln -s /path/to/symlink/source demo
  $ cd ../../..
  $ hg stat
  ? a/b/c/demo
  $ hg commit -A -m 'add symlink in a/b/c subdir'
  adding a/b/c/demo

2. clone it

  $ cd ..
  $ hg clone clone clonedest
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved


== symlink and git diffs ==

git symlink diff

  $ cd clonedest
  $ hg diff --git -r null:tip
  diff --git a/a/b/c/demo b/a/b/c/demo
  new file mode 120000
  --- /dev/null
  +++ b/a/b/c/demo
  @@ -0,0 +1,1 @@
  +/path/to/symlink/source
  \ No newline at end of file
  $ hg export --git tip > ../sl.diff

import git symlink diff

  $ hg rm a/b/c/demo
  $ hg commit -m'remove link'
  $ hg import ../sl.diff
  applying ../sl.diff
  $ hg diff --git -r 1:tip
  diff --git a/a/b/c/demo b/a/b/c/demo
  new file mode 120000
  --- /dev/null
  +++ b/a/b/c/demo
  @@ -0,0 +1,1 @@
  +/path/to/symlink/source
  \ No newline at end of file

== symlinks and addremove ==

directory moved and symlinked

  $ mkdir foo
  $ touch foo/a
  $ hg ci -Ama
  adding foo/a
  $ mv foo bar
  $ ln -s bar foo
  $ hg status
  ! foo/a
  ? bar/a
  ? foo

now addremove should remove old files

  $ hg addremove
  adding bar/a
  adding foo
  removing foo/a

commit and update back

  $ hg ci -mb
  $ hg up '.^'
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg up tip
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ cd ..

== root of repository is symlinked ==

  $ hg init root
  $ ln -s root link
  $ cd root
  $ echo foo > foo
  $ hg status
  ? foo
  $ hg status ../link
  ? foo
  $ hg add foo
  $ hg cp foo "$TESTTMP/link/bar"
  foo has not been committed yet, so no copy data will be stored for bar.
  $ cd ..


  $ hg init b
  $ cd b
  $ ln -s nothing dangling
  $ hg commit -m 'commit symlink without adding' dangling
  abort: dangling: file not tracked!
  [10]
  $ hg add dangling
  $ hg commit -m 'add symlink'

  $ hg tip -v
  changeset:   0:cabd88b706fc
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       dangling
  description:
  add symlink
  
  
  $ hg manifest --debug
  2564acbe54bbbedfbf608479340b359f04597f80 644 @ dangling
  $ readlink.py dangling
  dangling -> nothing

  $ rm dangling
  $ ln -s void dangling
  $ hg commit -m 'change symlink'
  $ readlink.py dangling
  dangling -> void


modifying link

  $ rm dangling
  $ ln -s empty dangling
  $ readlink.py dangling
  dangling -> empty


reverting to rev 0:

  $ hg revert -r 0 -a
  reverting dangling
  $ readlink.py dangling
  dangling -> nothing


backups:

  $ readlink.py *.orig
  dangling.orig -> empty
  $ rm *.orig
  $ hg up -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

copies

  $ hg cp -v dangling dangling2
  copying dangling to dangling2
  $ hg st -Cmard
  A dangling2
    dangling
  $ readlink.py dangling dangling2
  dangling -> void
  dangling2 -> void


Issue995: hg copy -A incorrectly handles symbolic links

  $ hg up -C
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ mkdir dir
  $ ln -s dir dirlink
  $ hg ci -qAm 'add dirlink'
  $ mkdir newdir
  $ mv dir newdir/dir
  $ mv dirlink newdir/dirlink
  $ hg mv -A dirlink newdir/dirlink

  $ cd ..