threads / patch / 55442

patchcompletion: treat unset GIT_COMPLETION_SHOW_ALL gracefully

Subject: [PATCH] completion: treat unset GIT_COMPLETION_SHOW_ALL gracefully

## tl;dr

3 messages between Apr 6, 2021 and Apr 8, 2021. Diffs are folded; open one to read it.

replies: 2people: 2as markdown or json

Ville Skyttä· Apr 6, 2021, 18:12 UTC · lore

If not set, referencing it in nounset (set -u) mode unguarded produces an error.

Signed-off-by: Ville Skyttä <ville.skytta@iki.fi>
---
 contrib/completion/git-completion.bash | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
Show changes to contrib/completion/git-completion.bash +1 −1
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index e1a66954fe..6d77f56f92 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -427,7 +427,7 @@ __gitcomp_builtin ()
 
 	if [ -z "$options" ]; then
 		local completion_helper
-		if [ "$GIT_COMPLETION_SHOW_ALL" = "1" ]; then
+		if [ "${GIT_COMPLETION_SHOW_ALL-}" = "1" ]; then
 			completion_helper="--git-completion-helper-all"
 		else
 			completion_helper="--git-completion-helper"
-- 
2.25.1
Junio C Hamano· Apr 6, 2021, 22:16 UTC · re: Ville Skyttä · lore

Re: [PATCH] completion: treat unset GIT_COMPLETION_SHOW_ALL gracefully

Ville Skyttä <ville.skytta@iki.fi> writes:
Show 7 quoted lines
> If not set, referencing it in nounset (set -u) mode unguarded produces
> an error.
>
> Signed-off-by: Ville Skyttä <ville.skytta@iki.fi>
> ---
>  contrib/completion/git-completion.bash | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
Thanks.
$ git grep -h -o -e '\$GIT_[A-Z_]*' master -- contrib/completion/git-completion.bash
gives a few other hits.

$GIT_DIR $GIT_COMPLETION_SHOW_ALL $GIT_TESTING_ALL_COMMAND_LIST $GIT_TESTING_ALL_COMMAND_LIST $GIT_TESTING_PORCELAIN_COMMAND_LIST

Have you gone through all of these hits?
I just checked that the reference to $GIT_DIR is safe.
        elif [ -n "${GIT_DIR-}" ]; then
                test -d "${GIT_DIR-}" &&
                __git_repo_path="$GIT_DIR"

In fact, after checking "is this non-empty?", the form used to see "is this a directory" does not even need to be "${VAR-}".

Among the two references to GIT_TESTING_ALL_COMMAND_LIST, the first one does not look safe to me, and that is what made me take a look myself. It probably wants to follow the same pattern as above, doesn't it? Or am I reading the code incorrectly and the use there is safe?

Reference to $GIT_TESTING_PORCELAIN_COMMAND_LIST is safe, as it follows the same "if test -n "${VAR-}"; then use "$VAR"; fi" pattern.

So, this patch definitely looks like an improvement, but if there are so few remaining issues, I'd prefer to see that (1) the proposed log message explain that the patch author audited all usages of variables and updated all "-u"-unsafe ones, and (2) the patch actually does update all remaining problematic ones.

If I am wrong about TESTING_ALL_COMMAND_LIST, then (2) may already be true, but then we want to describe that fact in the log message even more. It would ensure that future developers understand that ${VAR-} constructs are no accident and we are striving to make the script "-u"-safe.

Thanks.
Show 13 quoted lines
> diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
> index e1a66954fe..6d77f56f92 100644
> --- a/contrib/completion/git-completion.bash
> +++ b/contrib/completion/git-completion.bash
> @@ -427,7 +427,7 @@ __gitcomp_builtin ()
>  
>  	if [ -z "$options" ]; then
>  		local completion_helper
> -		if [ "$GIT_COMPLETION_SHOW_ALL" = "1" ]; then
> +		if [ "${GIT_COMPLETION_SHOW_ALL-}" = "1" ]; then
>  			completion_helper="--git-completion-helper-all"
>  		else
>  			completion_helper="--git-completion-helper"
Ville Skyttä· Apr 8, 2021, 06:52 UTC · re: Junio C Hamano · lore

Re: [PATCH] completion: treat unset GIT_COMPLETION_SHOW_ALL gracefully

On Wed, 7 Apr 2021 at 01:16, Junio C Hamano <gitster@pobox.com> wrote:
Show 16 quoted lines
>
> Ville Skyttä <ville.skytta@iki.fi> writes:
>
> > If not set, referencing it in nounset (set -u) mode unguarded produces
> > an error.
> >
> > Signed-off-by: Ville Skyttä <ville.skytta@iki.fi>
> > ---
> >  contrib/completion/git-completion.bash | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
>
> Thanks.
>
> $ git grep -h -o -e '\$GIT_[A-Z_]*' master -- contrib/completion/git-completion.bash
>
> gives a few other hits.
Thanks for checking. If we want to do what was proposed below:
> I'd prefer to see that (1) the proposed
> log message explain that the patch author audited all usages of
> variables

...we need to go through not only ones starting with GIT_, but as is written above, _all_ variables, which is a larger task.

To be clear, I haven't checked anything besides what was the subject of and change in the patch. I can go through all GIT_* while at it, but I'm not promising going through all variables at this point. Hopefully that's enough to get the resulting changes merged.

Would be great if there were some automated tests to catch these issues, as they tend to crop up over time.

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