summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJeff King <peff@peff.net>2015-10-28 18:44:21 -0400
committerJunio C Hamano <gitster@pobox.com>2015-10-29 12:10:23 -0700
commite34f80278e920e53b69016c7cecb24e4621e4564 (patch)
tree74ef9ebff60018e37116154b565a6fb87c20c69b
parent282616c72d1d08a77ca4fe1186cb708c38408d87 (diff)
downloadgit-e34f80278e920e53b69016c7cecb24e4621e4564.tar.gz
merge-file: clamp exit code to maximum 127jk/merge-file-exit-code
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 <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
-rw-r--r--Documentation/git-merge-file.txt3
-rw-r--r--builtin/merge-file.c3
-rwxr-xr-xt/t7600-merge.sh33
3 files changed, 38 insertions, 1 deletions
diff --git a/Documentation/git-merge-file.txt b/Documentation/git-merge-file.txt
index d2fc12ec77..f856032613 100644
--- a/Documentation/git-merge-file.txt
+++ b/Documentation/git-merge-file.txt
@@ -41,7 +41,8 @@ lines from `<other-file>`, or lines from both respectively. The length of the
conflict markers can be given with the `--marker-size` option.
The exit value of this program is negative on error, and the number of
-conflicts otherwise. If the merge was clean, the exit value is 0.
+conflicts otherwise (truncated to 127 if there are more than that many
+conflicts). If the merge was clean, the exit value is 0.
'git merge-file' is designed to be a minimal clone of RCS 'merge'; that is, it
implements all of RCS 'merge''s functionality which is needed by
diff --git a/builtin/merge-file.c b/builtin/merge-file.c
index 844f84f40b..ab4330a3d0 100644
--- a/builtin/merge-file.c
+++ b/builtin/merge-file.c
@@ -102,5 +102,8 @@ int cmd_merge_file(int argc, const char **argv, const char *prefix)
free(result.ptr);
}
+ if (ret > 127)
+ ret = 127;
+
return ret;
}
diff --git a/t/t7600-merge.sh b/t/t7600-merge.sh
index b16462132f..ede496c76b 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/ <file >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/ <file >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