[PATCH v2] t5314: check exit code of "git"

Amend the test added in [1] to check the exit code of the "git" invocations. An in-flight change[2] introduced a memory leak in these invocations, which went undetected unless we were running under "GIT_TEST_SANITIZE_LEAK_LOG=true".

Note that the in-flight change made 8 test files fail, but as far as I can tell only this one would have had its exit code hidden unless under "GIT_TEST_SANITIZE_LEAK_LOG=true". The rest would be caught without it.

We could pick other variable names here than "ln%d", e.g. "commit", "dummy_blob" and "file_blob", but having the "rev-parse" invocations aligned makes the difference between them more readable, so let's pick "ln%d".

1. 4cf2143e029 (pack-objects: break delta cycles before delta-search
   phase, 2016-08-11)
2. https://lore.kernel.org/git/221128.868rjvmi3l.gmgdl@evledraar.gmail.com/
3. faececa53f9 (test-lib: have the "check" mode for SANITIZE=leak
   consider leak logs, 2022-07-28)

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
Range-diff against v1:
1:  45b240740eb ! 1:  ca77a7249e6 t5314: check exit code of "rev-parse"
    @@ Metadata
     Author: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
     
      ## Commit message ##
    -    t5314: check exit code of "rev-parse"
    +    t5314: check exit code of "git"
     
    -    Amend the test added in [1] to check the exit code of the "rev-parse"
    +    Amend the test added in [1] to check the exit code of the "git"
         invocations. An in-flight change[2] introduced a memory leak in these
         invocations, which went undetected unless we were running under
         "GIT_TEST_SANITIZE_LEAK_LOG=true".
    @@ Commit message
         under "GIT_TEST_SANITIZE_LEAK_LOG=true". The rest would be caught
         without it.
     
    +    We could pick other variable names here than "ln%d", e.g. "commit",
    +    "dummy_blob" and "file_blob", but having the "rev-parse" invocations
    +    aligned makes the difference between them more readable, so let's pick
    +    "ln%d".
    +
         1. 4cf2143e029 (pack-objects: break delta cycles before delta-search
            phase, 2016-08-11)
         2. https://lore.kernel.org/git/221128.868rjvmi3l.gmgdl@evledraar.gmail.com/
    @@ t/t5314-pack-cycle-detection.sh: TEST_PASSES_SANITIZE_LEAK=true
     -	} |
     -	git pack-objects --stdout |
     -	git index-pack --stdin --fix-thin
    -+	grp1=$(git rev-parse "$2") &&
    -+	grp2=$(git rev-parse "$1:dummy") &&
    -+	grp3=$(git rev-parse "$1:file") &&
    ++	ln1=$(git rev-parse "$2") &&
    ++	ln2=$(git rev-parse "$1:dummy") &&
    ++	ln3=$(git rev-parse "$1:file") &&
     +	cat >list <<-EOF
    -+	-$grp1
    -+	$grp2 dummy
    -+	$grp3 file
    ++	-$ln1
    ++	$ln2 dummy
    ++	$ln3 file
     +	EOF
     +	git pack-objects --stdout <list >pack &&
     +	git index-pack --stdin --fix-thin <pack

 t/t5314-pack-cycle-detection.sh | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)