Re: [PATCH] Do not fail test if '.' is part of $PATH

[Jeff King <peff@peff.net>]

On Sat, Dec 01, 2018 at 06:07:57PM +0100, H.Merijn Brand wrote:

> When $PATH contains the current directory as .:PATH, PATH:., PATH:.:PATH,
> or (maybe worse) as :PATH, PATH:, or PATH::PATH - as an empty entry is
> identical to having dot in $PATH - this test used to fail

Good catch. The test cares about Git not accidentally adding "." to the
PATH, but we can't check that if it is already there.

> This patch was tested with PATH=$PATH, PATH=.:$PATH, PATH=$PATH:.,
> PATH=$PATH:.:/bin, PATH=:$PATH, PATH=$PATH:, and PATH=$PATH::/bin
> [...]
> +test_lazy_prereq DOT_IN_PATH '
> +       case ":$PATH:" in
> +       *:.:*|*::*) true  ;;
> +       *)          false ;;
> +       esac
> +'

Since the test is ultimately checking "can we run should-not-run from
the current directory", might it be simpler to actually try that as the
precondition? I.e., something like:

  test_expect_success 'create program in current directory' '
	write_script should-not-run <<-\EOF &&
	echo yikes
	EOF
  '

  test_lazy_prereq DOT_IN_PATH '
	should-not-run
  '

  test_expect_success !DOT_IN_PATH 'run_command is restricted to PATH' '
	test_must_fail test-tool run-command run-command should-not-run
  '

?

That's more lines, but we don't have to peek into the details of how
$PATH works.

-Peff