[PATCH 3/6] t1600-index: disable GIT_TEST_SPLIT_INDEX

Tests in 't1600-index.sh' check that various bogus index version
values are recognized and an appropriate warning message is issued.
GIT_TEST_SPLIT_INDEX=1 is supposed to trigger index splitting
randomly, and thus might interfere [1] with these tests: splitting the
index means that two index files are written (the shared base index
and the split '.git/index'), and the same warning message is then
issued twice, failing these tests.

Unset GIT_TEST_SPLIT_INDEX in this test script to avoid such
interference.

[1] There is no such interference at the moment, because, alas,
    GIT_TEST_SPLIT_INDEX=1 is broken and never split the index.  There
    was no such interference in the past (before it broke) either,
    because the first index write with GIT_TEST_SPLIT_INDEX=1 never
    split the index, only the second write did.  A subsequent commit
    fixing GIT_TEST_SPLIT_INDEX will have all the details on this.

Signed-off-by: SZEDER Gábor <redacted>
---
 t/t1600-index.sh | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/t/t1600-index.sh b/t/t1600-index.sh
index aa88fc30ce..46329c488b 100755
--- a/t/t1600-index.sh
+++ b/t/t1600-index.sh

@@ -4,6 +4,8 @@ test_description='index file specific tests'
 
 . ./test-lib.sh
 
+sane_unset GIT_TEST_SPLIT_INDEX
+
 test_expect_success 'setup' '
 	echo 1 >a
 '

-- 
2.33.0.453.gc5e41af357