view tests/test-rebase-templates.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 templating for rebase command

Setup

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > [experimental]
  > evolution=createmarkers
  > EOF

  $ hg init repo
  $ cd repo
  $ for ch in a b c d; do echo foo > $ch; hg commit -Aqm "Added "$ch; done

  $ hg log -G -T "{rev}:{node|short} {desc}"
  @  3:62615734edd5 Added d
  |
  o  2:28ad74487de9 Added c
  |
  o  1:29becc82797a Added b
  |
  o  0:18d04c59bb5d Added a
  
Getting the JSON output for nodechanges

  $ hg rebase -s 2 -d 0 -q -Tjson
  [
   {
    "nodechanges": {"28ad74487de9599d00d81085be739c61fc340652": ["849767420fd5519cf0026232411a943ed03cc9fb"], "62615734edd52f06b6fb9c2beb429e4fe30d57b8": ["df21b32134ba85d86bca590cbe9b8b7cbc346c53"]}
   }
  ]

  $ hg log -G -T "{rev}:{node|short} {desc}"
  @  5:df21b32134ba Added d
  |
  o  4:849767420fd5 Added c
  |
  | o  1:29becc82797a Added b
  |/
  o  0:18d04c59bb5d Added a
  
  $ hg rebase -s 1 -d 5 -q -T "{nodechanges|json}"
  {"29becc82797a4bc11ec8880b58eaecd2ab3e7760": ["d9d6773efc831c274eace04bc13e8e6412517139"]} (no-eol)

  $ hg log -G -T "{rev}:{node|short} {desc}"
  o  6:d9d6773efc83 Added b
  |
  @  5:df21b32134ba Added d
  |
  o  4:849767420fd5 Added c
  |
  o  0:18d04c59bb5d Added a
  

  $ hg rebase -s 6 -d 4 -q -T "{nodechanges % '{oldnode}:{newnodes % ' {node} '}'}"
  d9d6773efc831c274eace04bc13e8e6412517139: f48cd65c6dc3d2acb55da54402a5b029546e546f  (no-eol)

  $ hg log -G -T "{rev}:{node|short} {desc}"
  o  7:f48cd65c6dc3 Added b
  |
  | @  5:df21b32134ba Added d
  |/
  o  4:849767420fd5 Added c
  |
  o  0:18d04c59bb5d Added a
  


  $ hg rebase -s 7 -d 5 -q --keep -T "{nodechanges % '{oldnode}:{newnodes % ' {node} '}'}"
  f48cd65c6dc3d2acb55da54402a5b029546e546f: 6f7dda91e55e728fb798f3e44dbecf0ebaa83267  (no-eol)

  $ hg log -G -T "{rev}:{node|short} {desc}"
  o  8:6f7dda91e55e Added b
  |
  | o  7:f48cd65c6dc3 Added b
  | |
  @ |  5:df21b32134ba Added d
  |/
  o  4:849767420fd5 Added c
  |
  o  0:18d04c59bb5d Added a
  

Respects command-templates.oneline-summary

  $ hg rebase -r 7 -d 8 -n --config command-templates.oneline-summary='rev: {rev}'
  starting dry-run rebase; repository will not be changed
  rebasing rev: 7
  note: not rebasing rev: 7, its destination already has all its changes
  dry-run rebase completed successfully; run without -n/--dry-run to perform this rebase


command-templates.oneline-summary.rebase overrides

  $ hg rebase -r 7 -d 8 -n \
  > --config command-templates.oneline-summary='global: {rev}' \
  > --config command-templates.oneline-summary.rebase='override: {rev}'
  starting dry-run rebase; repository will not be changed
  rebasing override: 7
  note: not rebasing override: 7, its destination already has all its changes
  dry-run rebase completed successfully; run without -n/--dry-run to perform this rebase


check namespaces and coloring (labels)

  $ hg tag -l -r 7 my-tag
  $ hg rebase -r 7 -d 8 -n
  starting dry-run rebase; repository will not be changed
  rebasing 7:f48cd65c6dc3 my-tag "Added b"
  note: not rebasing 7:f48cd65c6dc3 my-tag "Added b", its destination already has all its changes
  dry-run rebase completed successfully; run without -n/--dry-run to perform this rebase
  $ hg bookmark -r 7 my-bookmark
  $ hg rebase -r 7 -d 8 -n
  starting dry-run rebase; repository will not be changed
  rebasing 7:f48cd65c6dc3 my-bookmark my-tag "Added b"
  note: not rebasing 7:f48cd65c6dc3 my-bookmark my-tag "Added b", its destination already has all its changes
  dry-run rebase completed successfully; run without -n/--dry-run to perform this rebase
  $ hg rebase -r 7 -d 8 -n --color=debug
  [ ui.status|starting dry-run rebase; repository will not be changed]
  [ ui.status|rebasing [oneline-summary.changeset|7:f48cd65c6dc3] [oneline-summary.bookmarks|my-bookmark] [oneline-summary.tags|my-tag] "[oneline-summary.desc|Added b]"]
  [ ui.warning|note: not rebasing [oneline-summary.changeset|7:f48cd65c6dc3] [oneline-summary.bookmarks|my-bookmark] [oneline-summary.tags|my-tag] "[oneline-summary.desc|Added b]", its destination already has all its changes]
  [ ui.status|dry-run rebase completed successfully; run without -n/--dry-run to perform this rebase]