From e34f80278e920e53b69016c7cecb24e4621e4564 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Wed, 28 Oct 2015 18:44:21 -0400 Subject: merge-file: clamp exit code to maximum 127 Git-merge-file is documented to return one of three exit codes: - zero means the merge was successful - a negative number means an error occurred - a positive number indicates the number of conflicts Unfortunately, this all gets stuffed into an 8-bit return code. Which means that if you have 256 conflicts, this wraps to zero, and the merge appears to succeed (and commits a blob full of conflict-marker cruft!). This patch clamps the return value to a maximum of 127, which we should be able to safely represent everywhere. This also leaves 128-255 for other values. Shells (and some parts of git) will typically represent signal death as 128 plus the signal number. And negative values are typically coerced to an 8-bit unsigned value (so "return -1" ends up as 255). Technically negative returns have the same problem (e.g., "-256" wraps back to 0), but this is not a problem in practice, as the only negative value we use is "-1". Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- t/t7600-merge.sh | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 't/t7600-merge.sh') diff --git a/t/t7600-merge.sh b/t/t7600-merge.sh index b16462132..ede496c76 100755 --- a/t/t7600-merge.sh +++ b/t/t7600-merge.sh @@ -692,4 +692,37 @@ test_expect_success GPG 'merge --no-edit tag should skip editor' ' test_cmp actual expect ' +test_expect_success 'set up mod-256 conflict scenario' ' + # 256 near-identical stanzas... + for i in $(test_seq 1 256); do + for j in 1 2 3 4 5; do + echo $i-$j + done + done >file && + git add file && + git commit -m base && + + # one side changes the first line of each to "master" + sed s/-1/-master/ tmp && + mv tmp file && + git commit -am master && + + # and the other to "side"; merging the two will + # yield 256 separate conflicts + git checkout -b side HEAD^ && + sed s/-1/-side/ tmp && + mv tmp file && + git commit -am side +' + +test_expect_success 'merge detects mod-256 conflicts (recursive)' ' + git reset --hard && + test_must_fail git merge -s recursive master +' + +test_expect_success 'merge detects mod-256 conflicts (resolve)' ' + git reset --hard && + test_must_fail git merge -s resolve master +' + test_done -- cgit v1.2.1