On Wed, Jan 27, 2021 at 5:30 AM Derrick Stolee <stolee@xxxxxxxxx> wrote:
>
> On 1/26/2021 10:08 PM, Elijah Newren wrote:
> > On Mon, Jan 25, 2021 at 9:42 AM Derrick Stolee via GitGitGadget
> > <gitgitgadget@xxxxxxxxx> wrote:
> >>
> >> From: Derrick Stolee <dstolee@xxxxxxxxxxxxx>
> >>
> >> Add a new 'sparse-index' repo alongside the 'full-checkout' and
> >> 'sparse-checkout' repos in t1092-sparse-checkout-compatibility.sh. Also
> >> add run_on_sparse and test_sparse_match helpers. These helpers will be
> >> used when the sparse index is implemented.
> >>
> >> Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx>
> >> ---
> >> t/t1092-sparse-checkout-compatibility.sh | 29 ++++++++++++++++++++----
> >> 1 file changed, 25 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
> >> index 8cd3e5a8d22..8876eae0fe3 100755
> >> --- a/t/t1092-sparse-checkout-compatibility.sh
> >> +++ b/t/t1092-sparse-checkout-compatibility.sh
> >> @@ -7,6 +7,7 @@ test_description='compare full workdir to sparse workdir'
> >> test_expect_success 'setup' '
> >> git init initial-repo &&
> >> (
> >> + (GIT_TEST_SPARSE_INDEX=0 && export GIT_TEST_SPARSE_INDEX) &&
> >
> > I thought parentheses started a subshell; once the subshell ends,
> > wouldn't the setting of GIT_TEST_SPARSE_INDEX be thrown away?
>
> I think the "export" specifically pushes the setting out of the
> first level of subshell. This is the recommendation that comes up
You're having a child process change the environment variables of a
parent process? ...without some kind of gdb or other debugger
wizardry?
> if one runs
>
> export GIT_TEST_SPARSE_INDEX=1 &&
>
> inside a test on macOS, since this isn't completely portable.
Um, I think you meant to run
GIT_TEST_SPARSE_INDEX=0 &&
export GIT_TEST_SPARSE_INDEX &&
in order to avoid the unportable
export GIT_TEST_SPARSE_INDEX=0 &&
because
(GIT_TEST_SPARSE_INDEX=0 &&
export GIT_TEST_SPARSE_INDEX) &&
looks like a useless no-op. At least it would be in normal bash; is
the test harness doing some special magic with it? In normal bash,
the value definitely does NOT survive the subshell; (export just means
that subprocesses of the subshell where the environment variable is
set will see the value):
$ echo Before: $GIT_TEST_SPARSE_INDEX && (GIT_TEST_SPARSE_INDEX=0 &&
export GIT_TEST_SPARSE_INDEX) && echo After: $GIT_TEST_SPARSE_INDEX
Before:
After:
But in contrast, without the parentheses:
$ echo Before: $GIT_TEST_SPARSE_INDEX && GIT_TEST_SPARSE_INDEX=0 &&
export GIT_TEST_SPARSE_INDEX && echo After: $GIT_TEST_SPARSE_INDEX
Before:
After: 0
