Subject: Re: [PATCH 3/5] tests: explicitly skip `chmod` calls on Windows

From: Ævar Arnfjörð Bjarmason <[email-masked]>
Date: Thu, 11 Aug 2022 13:22:17 +0200

On Wed, Aug 10 2022, Johannes Schindelin via GitGitGadget wrote:

> From: Johannes Schindelin <[email-masked]>
> [...]
> However, this quirk is only in effect as long as `chmod` is run inside
> the pseudo Unix root directory structure or within the home directory.
> When run outside, such invocations fail like this:
>
> 	chmod: changing permissions of '<file>': Invalid argument

..ok, but...

> diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
> index 6da7273f1d5..7c63b22acab 100644
> --- a/t/test-lib-functions.sh
> +++ b/t/test-lib-functions.sh
> @@ -492,7 +492,10 @@ test_commit_bulk () {
>  # of a file in the working directory and add it to the index.
>  
>  test_chmod () {
> -	chmod "$@" &&
> +	if test_have_prereq !MINGW
> +	then
> +		chmod "$@"
> +	fi &&
>  	git update-index --add "--chmod=$@"
>  }
>  
> @@ -548,7 +551,10 @@ write_script () {
>  		echo "#!${2-"$SHELL_PATH"}" &&
>  		cat
>  	} >"$1" &&
> -	chmod +x "$1"
> +	if test_have_prereq !MINGW
> +	then
> +		chmod +x "$1"
> +	fi

... you get +x semantics by default, so we didn't need that "chmod +x"
in the first place?

The rest of "test_chmod" seems to *happen to* pass +x or -x, but we
don't care about that, regardless of the "pseudo Unix root directory"?

What if we get a "test_chmod -o <file>", won't this silently do the
wrong thing?

If so isn't something in this direction (untested) a more targeted &
obvious fix?:

diff --git a/t/test-lib.sh b/t/test-lib.sh
index 10258def7be..1c3b6692388 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1690,6 +1690,16 @@ case $uname_s in
 	find () {
 		/usr/bin/find "$@"
 	}
+	chmod () {
+		case "$1" in
+		+x|-x)
+			return;
+			;;
+		*)
+			;;
+		esac &&
+		/usr/bin/chmod "$@"
+	}
 	# git sees Windows-style pwd
 	pwd () {
 		builtin pwd -W