git-sh-prompt: bash: GIT_PS1_COMPRESSSPARSESTATE: unbound variable

Hey there.

Could it be that git-sh-prompt no longer works properly?

With git 2.31.1: $ . /usr/lib/git-core/git-sh-prompt $ PS1='[\u@\h \W$(__git_ps1 " (%s)")]\$ ' $ cd someGitRepo bash: GIT_PS1_COMPRESSSPARSESTATE: unbound variable $

Cheers, Chris.

Christoph Anton Mitterer <calestyo@scientia.net> writes:

Would

    $ set +u

fix it, I have to wonder?

Junio C Hamano <gitster@pobox.com> writes:

Assuming that the answer is yes,...

I do not know who maintains this contrib/ script, but here is what

$ git grep -e '\$GIT_PS1_' -e '\${GIT_PS1_[^}-]*}' contrib/completion

gave me a handful candidates for fixes. Randomly picking Elijah from the output of

    $ git shortlog --no-merges -sn --since=18.months  \
	contrib/completion/git-prompt.sh |
      head -n 1

for ideas.

Thanks.

 contrib/completion/git-prompt.sh | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

On Wed, May 12, 2021 at 9:13 PM Junio C Hamano <gitster@pobox.com> wrote:

Yeah, I accidentally was relying on undefined-translates-to-empty, which breaks under set -u. I can duplicate the precise error, and your fix below is exactly how I fixed it too, before seeing you posted the same fix.

I'll post a patch with you as author...and some questions on what to do with the rest of the commit message and attribution tags.

Elijah Newren <newren@gmail.com> writes:

Nah, please take full credit for it. It is more work to test the result of the change than just running a grep and coming up with "I wonder if this would work...".

Thanks for a sanity check.

Hey there.

I think I found another case of an unbound variable:

Completing e.g.: git commit --[press TAB]

gives: $ git commit --bash: GIT_COMPLETION_SHOW_ALL: unbound variable

with some debugging:
$ set -xv
$ git commit --+ __git_func_wrap __git_main
+ local cur words cword prev
+ _get_comp_words_by_ref -n =: cur words cword prev
+ local exclude flag i OPTIND=1
+ words=()
+ local cur cword words
+ upargs=()
+ upvars=()
+ local upargs upvars vcur vcword vprev vwords
+ getopts c:i:n:p:w: flag -n =: cur words cword prev
+ case $flag in
+ exclude==:
+ getopts c:i:n:p:w: flag -n =: cur words cword prev
+ [[ 6 -ge 3 ]]
+ case ${!OPTIND} in
+ vcur=cur
+ (( OPTIND += 1 ))
+ [[ 6 -ge 4 ]]
+ case ${!OPTIND} in
+ vwords=words
+ (( OPTIND += 1 ))
+ [[ 6 -ge 5 ]]
+ case ${!OPTIND} in
+ vcword=cword
+ (( OPTIND += 1 ))
+ [[ 6 -ge 6 ]]
+ case ${!OPTIND} in
+ vprev=prev
+ (( OPTIND += 1 ))
+ [[ 6 -ge 7 ]]
+ __get_cword_at_cursor_by_ref =: words cword cur
+ words=()
+ local cword words
+ __reassemble_comp_words_by_ref =: words cword
+ local exclude i j line ref
+ [[ -n =: ]]
+ exclude='[=:]'
+ printf -v cword %s 2
+ [[ -v exclude ]]
+ line='git commit --'
+ (( i = 0, j = 0 ))
+ (( i < 3 ))
+ [[ 0 -gt 0 ]]
+ ref='words[0]'
+ printf -v 'words[0]' %s git
+ line=' commit --'
+ (( i == COMP_CWORD ))
+ (( i++, j++ ))
+ (( i < 3 ))
+ [[ 1 -gt 0 ]]
+ [[ commit == +([=:]) ]]
+ ref='words[1]'
+ printf -v 'words[1]' %s commit
+ line=' --'
+ (( i == COMP_CWORD ))
+ (( i++, j++ ))
+ (( i < 3 ))
+ [[ 2 -gt 0 ]]
+ [[ -- == +([=:]) ]]
+ ref='words[2]'
+ printf -v 'words[2]' %s --
+ line=
+ (( i == COMP_CWORD ))
+ printf -v cword %s 2
+ (( i++, j++ ))
+ (( i < 3 ))
+ (( i == COMP_CWORD ))
+ local i cur= index=13 'lead=git commit --'
+ [[ 13 -gt 0 ]]
+ [[ -n git commit -- ]]
+ [[ -n gitcommit-- ]]
+ cur='git commit --'
+ (( i = 0 ))
+ (( i <= cword ))
+ [[ 13 -ge 3 ]]
+ [[ git != \g\i\t ]]
+ (( i < cword ))
+ local old_size=13
+ cur=' commit --'
+ local new_size=10
+ (( index -= old_size - new_size ))
+ (( ++i ))
+ (( i <= cword ))
+ [[ 10 -ge 6 ]]
+ [[  commi != \c\o\m\m\i\t ]]
+ cur='commit --'
+ (( index > 0 ))
+ (( index-- ))
+ [[ 9 -ge 6 ]]
+ [[ commit != \c\o\m\m\i\t ]]
+ (( i < cword ))
+ local old_size=9
+ cur=' --'
+ local new_size=3
+ (( index -= old_size - new_size ))
+ (( ++i ))
+ (( i <= cword ))
+ [[ 3 -ge 2 ]]
+ [[  - != \-\- ]]
+ cur=--
+ (( index > 0 ))
+ (( index-- ))
+ [[ 2 -ge 2 ]]
+ [[ -- != \-\- ]]
+ (( i < cword ))
+ (( ++i ))
+ (( i <= cword ))
+ [[ -n -- ]]
+ [[ ! -n -- ]]
+ (( index < 0 ))
+ local words cword cur
+ _upvars -a3 words git commit -- -v cword 2 -v cur --
+ (( 11 ))
+ (( 11 ))
+ case $1 in
+ [[ -n 3 ]]
+ printf %d 3
+ [[ -n words ]]
+ unset -v words
+ eval 'words=("${@:3:3}")'
words=("${@:3:3}")
++ words=("${@:3:3}")
+ shift 5
+ (( 6 ))
+ case $1 in
+ [[ -n cword ]]
+ unset -v cword
+ eval 'cword="$3"'
cword="$3"
++ cword=2
+ shift 3
+ (( 3 ))
+ case $1 in
+ [[ -n cur ]]
+ unset -v cur
+ eval 'cur="$3"'
cur="$3"
++ cur=--
+ shift 3
+ (( 0 ))
+ [[ -v vcur ]]
+ upvars+=("$vcur")
+ upargs+=(-v $vcur "$cur")
+ [[ -v vcword ]]
+ upvars+=("$vcword")
+ upargs+=(-v $vcword "$cword")
+ [[ -v vprev ]]
+ [[ 2 -ge 1 ]]
+ upvars+=("$vprev")
+ upargs+=(-v $vprev "${words[cword - 1]}")
+ [[ -v vwords ]]
+ upvars+=("$vwords")
+ upargs+=(-a${#words[@]} $vwords ${words+"${words[@]}"})
+ (( 4 ))
+ local cur cword prev words
+ _upvars -v cur -- -v cword 2 -v prev commit -a3 words git commit --
+ (( 14 ))
+ (( 14 ))
+ case $1 in
+ [[ -n cur ]]
+ unset -v cur
+ eval 'cur="$3"'
cur="$3"
++ cur=--
+ shift 3
+ (( 11 ))
+ case $1 in
+ [[ -n cword ]]
+ unset -v cword
+ eval 'cword="$3"'
cword="$3"
++ cword=2
+ shift 3
+ (( 8 ))
+ case $1 in
+ [[ -n prev ]]
+ unset -v prev
+ eval 'prev="$3"'
prev="$3"
++ prev=commit
+ shift 3
+ (( 5 ))
+ case $1 in
+ [[ -n 3 ]]
+ printf %d 3
+ [[ -n words ]]
+ unset -v words
+ eval 'words=("${@:3:3}")'
words=("${@:3:3}")
++ words=("${@:3:3}")
+ shift 5
+ (( 0 ))
+ __git_main
+ local i c=1 command __git_dir __git_repo_path
+ local __git_C_args C_args_count=0
+ '[' 1 -lt 2 ']'
+ i=commit
+ case "$i" in
+ command=commit
+ break
+ '[' -z commit ']'
+ __git_complete_command commit
+ local command=commit
+ local completion_func=_git_commit
+ __git_have_func _git_commit
+ declare -f -- _git_commit
+ __git_have_func _git_commit
+ declare -f -- _git_commit
+ _git_commit
+ case "$prev" in
+ case "$cur" in
+ __gitcomp_builtin commit
+ local cmd=commit
+ local incl=
+ local excl=
+ local var=__gitcomp_builtin_commit
+ local options
+ eval 'options=${__gitcomp_builtin_commit-}'
options=${__gitcomp_builtin_commit-}
++ options=
+ '[' -z '' ']'
+ local completion_helper
bash: GIT_COMPLETION_SHOW_ALL: unbound variable

These seem to be in: /usr/share/bash-completion/completions/git and possibly also: /usr/share/bash-completion/completions/gitk

Cheers, Chris.

Christoph Anton Mitterer <calestyo@scientia.net> writes:

It seems that OMIT_SPARSESTATE would have the same issue.

	if [ -z "${GIT_PS1_COMPRESSSPARSESTATE}" ] &&
	   [ -z "${GIT_PS1_OMITSPARSESTATE}" ] &&

all coming from afda36db (git-prompt: include sparsity state as well, 2020-06-21).

But I think we have already seen the fix in 5c0cbdb1 (git-prompt: work under set -u, 2021-05-13), which may or may not appear in the upcoming release.

There still are unprotected mentions of GIT_PS1_SHOWUPSTREAM even with that fix, though.

On Wed, May 19, 2021 at 4:29 PM Junio C Hamano <gitster@pobox.com> wrote:

That particular case was fixed by Ville Skyttä in commit c5c0548d793e (completion: audit and guard $GIT_* against unset use, 2021-04-08).

Yeah, I fixed the ones I introduced in git-prompt.sh -- GIT_PS1_COMPRESSSPARSESTATE and GIT_PS1_OMITSPARSESTATE.

Yeah, neither my fix (which was only trying to fix the problems I introduced in git-prompt.sh) nor Ville's fix (which was focused on git-completion.bash) caught that one.

Do you want to make a patch for that, Christoph?  If not, #leftoverbits?

On Thu, 2021-05-13 at 13:03 +0900, Junio C Hamano wrote:

Damn, I'm so blind ^^ Had recently set -u to try out whether unset variables are used anywhere. Yes it fixes it.

Thanks anyway for going to fix it :-)

Cheers, Chris.