This fixes a few unrelated issues:
- when ENABLE_MACHINED is false, machinectl is not installed, but _sd_machines
is still used in a few places that want to complete -M and such.
Also, bash completion calls machinectl in various places.
Make missing machinectl mean "no machines" in this case, so
that no error is generated in the callers.
- machinectl list --full would print multiple lines of output per machine,
breaking grep, issue introduced in e2268fa437.
Using --max-addresses=1 would fix the issue, but let's use
--max-addresses=0 because we now can.
- the lists used in various places were slightly different for no good reason.
- don't use a subshell if not necessary.
The code for bash still uses the same combined list of images and running
machines for various commands. The zsh code uses images for start/clone, and
running machines for the rest. Maybe something to fix in the future.
Replaces #25048.
The words and cword variables are not localized in all Bash completion
scripts that call _init_completion.
cur, prev, words, and cword (and split if using the -s flag) are all
variables that should be localized in Bash completion scripts before
calling _init_completion (even if they don't otherwise appear in the
calling script). This is done for cur and prev, but not for words and
cword. Letting words and cword remain unlocalized may clobber variables
the user is using for other purposes, which is bad.
This issue can be resolved by declaring words and cword as local
variables.
Resolves#19188.
