view tests/test-merge-exec.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

===============================================
Testing merge involving change to the exec flag
===============================================

#require execbit

Initial setup
==============


  $ hg init base-repo
  $ cd base-repo
  $ cat << EOF > a
  > 1
  > 2
  > 3
  > 4
  > 5
  > 6
  > 7
  > 8
  > 9
  > EOF
  $ touch b
  $ hg add a b
  $ hg commit -m "initial commit"
  $ cd ..

  $ hg init base-exec
  $ cd base-exec
  $ cat << EOF > a
  > 1
  > 2
  > 3
  > 4
  > 5
  > 6
  > 7
  > 8
  > 9
  > EOF
  $ chmod +x a
  $ touch b
  $ hg add a b
  $ hg commit -m "initial commit"
  $ cd ..

Testing merging mode change
===========================

Adding the flag
---------------

setup

Change on one side, executable bit on the other

  $ hg clone base-repo simple-merge-repo
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd simple-merge-repo
  $ chmod +x a
  $ hg ci -m "make a executable, no change"
  $ [ -x a ] || echo "executable bit not recorded"
  $ hg up ".^"
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat << EOF > a
  > 1
  > 2
  > 3
  > 4
  > 5
  > 6
  > 7
  > x
  > 9
  > EOF
  $ hg commit -m "edit end of file"
  created new head

merge them (from the update side)

  $ hg merge 'desc("make a executable, no change")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st
  M a
  $ [ -x a ] || echo "executable bit lost"

merge them (from the chmod side)

  $ hg up -C 'desc("make a executable, no change")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge 'desc("edit end of file")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st
  M a
  $ [ -x a ] || echo "executable bit lost"


  $ cd ..


Removing the flag
-----------------

Change on one side, executable bit on the other

  $ hg clone base-exec simple-merge-repo-removal
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd simple-merge-repo-removal
  $ chmod -x a
  $ hg ci -m "make a non-executable, no change"
  $ [ -x a ] && echo "executable bit not removed"
  [1]
  $ hg up ".^"
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat << EOF > a
  > 1
  > 2
  > 3
  > 4
  > 5
  > 6
  > 7
  > x
  > 9
  > EOF
  $ hg commit -m "edit end of file"
  created new head

merge them (from the update side)

  $ hg merge 'desc("make a non-executable, no change")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st
  M a
  $ [ -x a ] && echo "executable bit not removed"
  [1]

merge them (from the chmod side)

  $ hg up -C 'desc("make a non-executable, no change")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge 'desc("edit end of file")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st
  M a
  $ [ -x a ] && echo "executable bit not removed"
  [1]


  $ cd ..

Testing merging mode change with rename
=======================================

Adding the flag
---------------

  $ hg clone base-repo rename-merge-repo
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd rename-merge-repo

make "a" executable on one side

  $ chmod +x a
  $ hg status
  M a
  $ hg ci -m "make a executable"
  $ [ -x a ] || echo "executable bit not recorded"
  $ hg up ".^"
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

make "a" renamed on the other side

  $ hg mv a z
  $ hg st --copies
  A z
    a
  R a
  $ hg ci -m "rename a to z"
  created new head

merge them (from the rename side)

  $ hg merge 'desc("make a executable")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st --copies
  M z
    a
  $ [ -x z ] || echo "executable bit lost"

merge them (from the chmod side)

  $ hg up -C 'desc("make a executable")'
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge 'desc("rename a to z")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st --copies
  M z
    a
  R a
  $ [ -x z ] || echo "executable bit lost"


  $ cd ..

Removing the flag
-----------------

  $ hg clone base-exec rename-merge-repo-removal
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd rename-merge-repo-removal

make "a" non-executable on one side

  $ chmod -x a
  $ hg status
  M a
  $ hg ci -m "make a non-executable"
  $ [ -x a ] && echo "executable bit not removed"
  [1]
  $ hg up ".^"
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

make "a" renamed on the other side

  $ hg mv a z
  $ hg st --copies
  A z
    a
  R a
  $ hg ci -m "rename a to z"
  created new head

merge them (from the rename side)

  $ hg merge 'desc("make a non-executable")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st --copies
  M z
    a
  $ [ -x z ] && echo "executable bit not removed"
  [1]

merge them (from the chmod side)

  $ hg up -C 'desc("make a non-executable")'
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge 'desc("rename a to z")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st --copies
  M z
    a
  R a
  $ [ -x z ] && echo "executable bit not removed"
  [1]


  $ cd ..


Testing merging mode change with rename + modification on both side
===================================================================


Adding the flag
---------------

  $ hg clone base-repo rename+mod-merge-repo
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd rename+mod-merge-repo

make "a" executable on one side

  $ chmod +x a
  $ cat << EOF > a
  > 1
  > x
  > 3
  > 4
  > 5
  > 6
  > 7
  > 8
  > 9
  > EOF
  $ hg status
  M a
  $ hg ci -m "make a executable, and change start"
  $ [ -x a ] || echo "executable bit not recorded"
  $ hg up ".^"
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

make "a" renamed on the other side

  $ hg mv a z
  $ hg st --copies
  A z
    a
  R a
  $ cat << EOF > z
  > 1
  > 2
  > 3
  > 4
  > 5
  > 6
  > 7
  > x
  > 9
  > EOF
  $ hg ci -m "rename a to z, and change end"
  created new head

merge them (from the rename side)

  $ hg merge 'desc("make a executable")'
  merging z and a to z
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st --copies
  M z
    a
  $ [ -x z ] || echo "executable bit lost"

merge them (from the chmod side)

  $ hg up -C 'desc("make a executable")'
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge 'desc("rename a to z")'
  merging a and z to z
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st --copies
  M z
    a
  R a
  $ [ -x z ] || echo "executable bit lost"

  $ cd ..

Removing the flag
-----------------

  $ hg clone base-exec rename+mod-merge-repo-removal
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd rename+mod-merge-repo-removal

make "a" non-executable on one side

  $ chmod -x a
  $ cat << EOF > a
  > 1
  > x
  > 3
  > 4
  > 5
  > 6
  > 7
  > 8
  > 9
  > EOF
  $ hg status
  M a
  $ hg ci -m "make a non-executable, and change start"
  $ [ -x z ] && echo "executable bit not removed"
  [1]
  $ hg up ".^"
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

make "a" renamed on the other side

  $ hg mv a z
  $ hg st --copies
  A z
    a
  R a
  $ cat << EOF > z
  > 1
  > 2
  > 3
  > 4
  > 5
  > 6
  > 7
  > x
  > 9
  > EOF
  $ hg ci -m "rename a to z, and change end"
  created new head

merge them (from the rename side)

  $ hg merge 'desc("make a non-executable")'
  merging z and a to z
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st --copies
  M z
    a
  $ [ -x z ] && echo "executable bit not removed"
  [1]

merge them (from the chmod side)

  $ hg up -C 'desc("make a non-executable")'
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge 'desc("rename a to z")'
  merging a and z to z
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st --copies
  M z
    a
  R a
  $ [ -x z ] && echo "executable bit not removed"
  [1]

  $ cd ..