[ANNOUNCE] libxkbcommon 1.6.0

[Ran Benita]

This release contains the accumulated changes to xkbcommon from the last ~year.
I'm happy to announce we are joined by a new maintainer, Pierre Le Marre
(Wismill), who wrote the majority of features, bug fixes and documentation
improvements in this release, with very high care and quality. Welcome Pierre!

libxkbcommon 1.6.0
==================

API
---

### Breaking changes

- *Remove* keysyms that were intended for German T3 layout but are unused:

  - `XKB_KEY_dead_lowline`
  - `XKB_KEY_dead_aboveverticalline`
  - `XKB_KEY_dead_belowverticalline`
  - `XKB_KEY_dead_longsolidusoverlay`

  See the upstream
  [`xorgproto` MR](https://gitlab.freedesktop.org/xorg/proto/xorgproto/-/merge_requests/70).
  See hereinafter for further changes related to keysyms.

### New

- Add Compose iterator API to iterate the entries in a compose table:

  - `xkb_compose_table_entry_sequence`
  - `xkb_compose_table_entry_keysym`
  - `xkb_compose_table_entry_utf8`
  - `xkb_compose_table_iterator_new`
  - `xkb_compose_table_iterator_free`
  - `xkb_compose_table_iterator_next`

- *Structured log messages* with a message registry. There is an *ongoing* work
  to assign unique identifiers to log messages and add a corresponding error
  index documentation page:

  - The log entries are preceded with an identifier in the form `XKB-NNN`,
    where `NNN` is a decimal number.

  - The log entries can then be parsed with third-party tools, to check for
    specific identifiers.

  - The new documentation page “**Error index**” lists all the kind of error
    messages with their identifiers. The aim is that each entry could present
    detailed information on the error and how to fix it.

- Add a new warning for numeric keysyms references in XKB files: the preferred
  keysym reference form is its name or its Unicode value, if relevant.

- Add the upper bound `XKB_KEYSYM_MAX` to check valid keysyms.

- Add a warning when loading a keymap using RMLVO with no layout but with the
  variant set. The variant is actually discarded and both layout and variant
  are set to default values, but this was done previously with no warning,
  confusing end users.

- Add support for `modifier_map None { … }`. This feature is missing compared
  to the X11 implementation. It allows to reset the modifier map of a key.

- Update keysyms using latest [xorgproto]
  (commit: `1c8128d72df22843a2022576850bc5ab5e3a46ea`):

  - Additions:

    - `XKB_KEY_ordmasculine` ([xorgproto-68])
    - `XKB_KEY_guillemetleft` ([xorgproto-68])
    - `XKB_KEY_guillemetright` ([xorgproto-68])
    - `XKB_KEY_dead_schwa` ([xorgproto-78])
    - `XKB_KEY_dead_SCHWA` ([xorgproto-78])
    - `XKB_KEY_dead_hamza` ([xorgproto-71])
    - `XKB_KEY_XF86EmojiPicker` ([xorgproto-44])
    - `XKB_KEY_XF86Dictate` ([xorgproto-49])
    - `XKB_KEY_XF86CameraAccessEnable` ([xorgproto-82])
    - `XKB_KEY_XF86CameraAccessDisable` ([xorgproto-82])
    - `XKB_KEY_XF86CameraAccessToggle` ([xorgproto-82])
    - `XKB_KEY_XF86NextElement` ([xorgproto-82])
    - `XKB_KEY_XF86PreviousElement` ([xorgproto-82])
    - `XKB_KEY_XF86AutopilotEngageToggle` ([xorgproto-82])
    - `XKB_KEY_XF86MarkWaypoint` ([xorgproto-82])
    - `XKB_KEY_XF86Sos` ([xorgproto-82])
    - `XKB_KEY_XF86NavChart` ([xorgproto-82])
    - `XKB_KEY_XF86FishingChart` ([xorgproto-82])
    - `XKB_KEY_XF86SingleRangeRadar` ([xorgproto-82])
    - `XKB_KEY_XF86DualRangeRadar` ([xorgproto-82])
    - `XKB_KEY_XF86RadarOverlay` ([xorgproto-82])
    - `XKB_KEY_XF86TraditionalSonar` ([xorgproto-82])
    - `XKB_KEY_XF86ClearvuSonar` ([xorgproto-82])
    - `XKB_KEY_XF86SidevuSonar` ([xorgproto-82])
    - `XKB_KEY_XF86NavInfo` ([xorgproto-82])

  - Deprecations:

    - `XKB_KEY_masculine`: use `XKB_KEY_ordmasculine` instead ([xorgproto-68])
    - `XKB_KEY_guillemotleft`: use `XKB_KEY_guillemetleft` instead ([xorgproto-68])
    - `XKB_KEY_guillemotright`: use `XKB_KEY_guillemetright` instead ([xorgproto-68])
    - `XKB_KEY_dead_small_schwa`: use `XKB_KEY_dead_schwa` instead ([xorgproto-78])
    - `XKB_KEY_dead_capital_schwa`: use `XKB_KEY_dead_SCHWA` instead ([xorgproto-78])

  [xorgproto]: https://gitlab.freedesktop.org/xorg/proto/xorgproto
  [xorgproto-44]: https://gitlab.freedesktop.org/xorg/proto/xorgproto/-/merge_requests/44
  [xorgproto-49]: https://gitlab.freedesktop.org/xorg/proto/xorgproto/-/merge_requests/49
  [xorgproto-68]: https://gitlab.freedesktop.org/xorg/proto/xorgproto/-/merge_requests/68
  [xorgproto-71]: https://gitlab.freedesktop.org/xorg/proto/xorgproto/-/merge_requests/71
  [xorgproto-78]: https://gitlab.freedesktop.org/xorg/proto/xorgproto/-/merge_requests/78
  [xorgproto-82]: https://gitlab.freedesktop.org/xorg/proto/xorgproto/-/merge_requests/82

- Ongoing work to improve the documentation about XKB and its V1 format.

### Fixes

- Prevent `xkb_keysym_from_name` to parse out-of-range hexadecimal keysyms.

- Disallow producing NULL character with escape sequences `\0` and `\x0`.

- Prevent overflow of octal escape sequences by making `\400..\777` invalid.

- Prevent interpreting and emitting invalid Unicode encoding forms: surrogates
  are invalid in both UTF-32 and UTF-8.

- `xkb_keymap_new_from_buffer`: Allow for a NULL-terminated keymap string.

- Compose: Increase the limit of possible entries to handle huge Compose files.

Tools
-----

### New

- Add bash completions for `xkbcli` and its subcommands.

- `xkbcli interactive-*`: Add options `--short` to hide some fields.

- `xkbcli interactive-evdev`: Add `--includes` and `--include-defaults` options.

- Add `xkb-check-messages` *experimental* tool (not installed).
  It checks whether given log messages identifiers are supported.

### Fixes

- `xkbcli compile-keymap`: Allow to use without arguments.

- `xkbcli interactive-*`: Always print keycode.

- `xkbcli interactive-*`: Escape control characters for Unicode output, instead of
  printing them as-is, messing the output.

Build system
------------

- Bump required meson to 0.52.0.

- Allow `xkbcommon` to be used as a subproject.

- Improve Windows compilation.


Tarball:
--------

git tag: xkbcommon-1.6.0

https://xkbcommon.org/download/libxkbcommon-1.6.0.tar.xz

SHA-256: 0edc14eccdd391514458bc5f5a4b99863ed2d651e4dd761a90abf4f46ef99c2b libxkbcommon-1.6.0.tar.xz

Ran