[Bug report] superuser detection brittleness

[crgr]

Is there an existing issue for this?

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Update the issue title

• I have updated the title

Expected Behavior

zsh-abbr loads normally

Actual Behavior

zsh-abbr fails silently

Steps To Reproduce

running exec zsh -xv reveals

• zsh:86> [[ '' == \ # ]]
  zsh:86: parse error near `#'

line 86 reads:

86 if [[ ${(%):-%#} == '#' ]]; then

trying to escape the # character with a backslash \ works in some contexts in Zsh, however within the [[ ... ]] conditional expression and especially in combination with the parameter expansion flags, is causing a parse error. Zsh is misinterpreting # in this context.

Environment

~ # abbr profile
zsh-abbr version 6.2.1
zsh 5.9 (x86_64-debian-linux-gnu)
OSTYPE linux-gnu

Installation method

Manual

Installation method details

~ # echo $ABBR_SOURCE_PATH
/opt/zsh-abbr

Anything else?

replacing line 86 with

86 if [[ "%#" == '#' ]]; then

makes it work again

[olets]

Thanks for the report, and for looking through the -xv output.

I can't replicate the error: starting from a non-privileged user, I get

% exec zsh -xv
# snip
+/[snip]/zsh-abbr.zsh:86> [[ % == \# ]]
# no "parse error"
# snip

And the suggested change breaks support for distinct tempdirs for privileged and unprivileged users.

• With 6.2.1 unchanged, I get

  % echo ${${ABBR_TMPDIR:-${${TMPDIR:-/tmp}%/}/zsh-abbr}%/}/
  # a path
  % echo ${${ABBR_TMPDIR:-${${TMPDIR:-/tmp}%/}/zsh-abbr-privileged-users}%/}/
  # a different path
  % echo $_abbr_tmpdir
  # same as the first path
  % sudo zsh
  % echo ${${ABBR_TMPDIR:-${${TMPDIR:-/tmp}%/}/zsh-abbr}%/}/
  # a path
  % echo ${${ABBR_TMPDIR:-${${TMPDIR:-/tmp}%/}/zsh-abbr-privileged-users}%/}/
  # a different path
  % echo $_abbr_tmpdir
  # same as the second path

• With the suggested change, I get

  % echo ${${ABBR_TMPDIR:-${${TMPDIR:-/tmp}%/}/zsh-abbr}%/}/
  # a path
  % echo ${${ABBR_TMPDIR:-${${TMPDIR:-/tmp}%/}/zsh-abbr-privileged-users}%/}/
  # a different path
  % echo $_abbr_tmpdir
  # same as the first path
  % sudo zsh
  % echo ${${ABBR_TMPDIR:-${${TMPDIR:-/tmp}%/}/zsh-abbr}%/}/
  # a path
  % echo ${${ABBR_TMPDIR:-${${TMPDIR:-/tmp}%/}/zsh-abbr-privileged-users}%/}/
  # a different path
  % echo $_abbr_tmpdir
  # same as the FIRST path ⚠️ BAD

//

This makes me realize it'd be good to add a config var for the privileged user tmpdir

- ${${ABBR_TMPDIR:-${${TMPDIR:-/tmp}%/}/zsh-abbr-privileged-users}%/}/
+ ${${${ABBR_TMPDIR_PRIVILEGED_USERS:-ABBR_TMPDIR}:-${${TMPDIR:-/tmp}%/}/zsh-abbr-privileged-users}%/}/

//

This will take some more investigation.

• What happens if you do

  % [[ ${(%):-%#} == '#' ]] && { echo y } || echo n
  % sudo zsh
  % [[ ${(%):-%#} == '#' ]] && { echo y } || echo n

  I get n and then y. Do you get n and then an error?

• Tell me more about "zsh-abbr fails silently". What tipped you off that something was going wrong?

[crgr]

Thank you for the swift reply and for the wonderful piece of code that zsh-abbr is.

I got an n and then the y too, no errors.

What tipped me off that something went wrong was the red zsh prompt right after login. I have a very minimalistic .zshrc:

PS1='%F{blue}%~ %(?.%F{green}.%F{red})%#%f '
source "/opt/zsh-abbr/zsh-abbr.zsh"

I immediately echo $? and it was 1.

[olets]

I've pushed up a fix attempt in the new branch issues/166. If you have a chance to try it out, I'd be interested to hear the result!

[crgr]

running issues/166 as root is fine but trying to run it as a non-privileged user is problematic:

_job_queue:push:add_job:7: permission denied: /tmp/zsh-job-queue/zsh-abbr/1740627352.4137823582--RV2hCM8cECJtrbGWfwKjxDTG7BAQoCWPk8fL
_job_queue:push:add_job:8: permission denied: /tmp/zsh-job-queue/zsh-abbr/1740627352.4137823582--RV2hCM8cECJtrbGWfwKjxDTG7BAQoCWPk8fL
_job_queue:push:wait_turn:6: bad math expression: operand expected at end of string
_abbr_load_user_abbreviations:load:42: permission denied: /tmp/zsh-abbr/regular-user-abbreviations
_abbr_load_user_abbreviations:load:43: permission denied: /tmp/zsh-abbr/global-user-abbreviations

[olets]

Thanks!

Bummer.

Might be a week and a half minimum before I have zsh-abbr time again. But we'll figure this out eventually…