_precommand lets zsh complete other commands and their arguments
e.g. it can complete grep with "systemd-cat gr" and complete grep options
with "systemd-cat grep -"
* fix error
* remove options that are no longer supported
* add missing options
* stop completion if an option `--help` or `--version` is supplied
[[[
zjs: a note for the reader:
zshcompsys(1) in the section about optspecs in _arguments says:
> Each of the forms above may be preceded by a list in parentheses of option names and argument num‐
> bers. If the given option is on the command line, the options and arguments indicated in parentheses
> will not be offered. For example, ‘(-two -three 1)-one:...' completes the option ‘-one'; if this ap‐
> pears on the command line, the options -two and -three and the first ordinary argument will not be
> completed after it. ‘(-foo):...' specifies an ordinary argument completion; -foo will not be com‐
> pleted if that argument is already present.
>
> Other items may appear in the list of excluded options to indicate various other items that should
> not be applied when the current specification is matched: a single star (\*) for the rest arguments
> (i.e. a specification of the form ‘\*:...'); a colon (:) for all normal (non-option-) arguments; and a
> hyphen (-) for all options. For example, if ‘(\*)' appears before an option and the option appears on
> the command line, the list of remaining arguments (those shown in the above table beginning with
> ‘\*:') will not be completed.
The intended effect of the change is to remove irrelevant completion matches from the completion.
tl;dr: (- : ) prevents further completion
]]]
These will be used by display managers to pre-select the user's
preferred desktop environment and display server type. On homed, the
display manager will also be able to set these fields to cache the
user's last selection.
This makes it possible to edit blob directories using homectl. The
following syntax is available:
* `--blob-directory=/path/somewhere`: Replaces the entire blob directory
with the contents of /path/somewhere
* `--blob-directory=foobar=/path/somewhere`: Replaces just the file
foobar in the blob directory with the contents of /path/somewhere
* `--blob-directory=foobar=`: Deletes the file foobar from the blob
directory
* `--blob-directory=`: Resets all previous flags
* `--avatar=`, etc: Shortcuts for `--blob-directory=FILENAME=` for the
known files in the blob directory
This field is like preferredLanguage, but takes a priority list of
languages instead. If an app isn't translated into a user's primary
language, it can fall back to one of the other languages in the list
thus making the app more accessible to the user.
For instance: in my experience, many Ukrainians are fluent in Russian,
often significantly better than English (especially if they are of a
generation that grew up during the USSR). Such a person might set this
new variable to ["uk_UA.UTF-8", "ru_UA.UTF-8"] so that software that
lacks Ukrainian translations will first try Russian translations before
defaulting to English.
Fixes#31290
