45424: completion: Add **/sbin to PATH when completing commands like sudo

* Update _command_names to add **/sbin to PATH when not otherwise overridden
  and _comp_priv_prefix is set. This ensures that, on systems where
  unprivileged users don't have **/sbin in their PATHs, we can still complete
  those commands when they try to run them with e.g. sudo

* Update functions for privilege-gaining commands to use the aforementioned
  mechanism

* Fix some other minor issues in _pfexec and _doas

Changes from the posted diff:

* Fix a minor redundancy in _doas

* Add _c_p_p=( '' ) hack to _su

1 files changed, 9 insertions, 5 deletions

diff --git a/Completion/Unix/Command/_sudo b/Completion/Unix/Command/_sudo
index 41e32cbae..e3d12d72f 100644
--- a/Completion/Unix/Command/_sudo
+++ b/Completion/Unix/Command/_sudo
@@ -2,9 +2,9 @@
 
 setopt localoptions extended_glob
 
-local environ e cmd
-local -a args
-local -a _comp_priv_prefix
+local environ e cmd cpp
+local -a args _comp_priv_prefix
+local -A opt_args
 
 zstyle -a ":completion:${curcontext}:" environ environ
 
@@ -42,6 +42,10 @@ if [[ $service = sudoedit ]] || (( $words[(i)-e] < $words[(i)^(*sudo|-[^-]*)] ))
   args=( -A "-*" $args '!(-V --version -h --help)-e' '*:file:_files' )
 else
   cmd="$words[1]"
+  cpp='_comp_priv_prefix=(
+    $cmd -n
+    ${(kv)opt_args[(I)(-[ugHEP]|--(user|group|set-home|preserve-env|preserve-groups))]}
+  )'
   args+=(
     '(-e --edit 1 *)'{-e,--edit}'[edit files instead of running a command]' \
     '(-s --shell)'{-s,--shell}'[run shell as the target user; a command may also be specified]' \
@@ -51,8 +55,8 @@ else
     '(-E -i --login -s --shell -e --edit)--preserve-env=-[preserve user environment when running command]::environment variable:_sequence _parameters -g "*export*"' \
     '(-H --set-home -i --login -s --shell -e --edit)'{-H,--set-home}"[set HOME variable to target user's home dir]" \
     '(-P --preserve-groups -i -login -s --shell -e --edit)'{-P,--preserve-groups}"[preserve group vector instead of setting to target's]" \
-    '(-)1:command: _command_names -e'
-    '*::arguments:{ _comp_priv_prefix=( $cmd -n ${(kv)opt_args[(I)(-[ugHEP]|--(user|group|set-home|preserve-env|preserve-groups))]} ) ; _normal }'
+    "(-)1: :{ $cpp; _command_names -e }"
+    "*:: :{ $cpp; _normal }"
   )
 fi