From: Antonin Delpeuch <antonin@xxxxxxxxxxx>
The current default diff algorithm for the merge-file command is
'myers', despite the default for the 'ort' strategy being 'histogram'.
Since 2.44.0 it is possible to specify a different diff algorithm via
the --diff-algorithm option. As a preparation for changing the default
to 'histogram', we warn the user about the different behaviour this
may cause.
Signed-off-by: Antonin Delpeuch <antonin@xxxxxxxxxxx>
---
merge-file: warn for implicit 'myers' algorithm
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1741%2Fwetneb%2Fexplicit_diff_algorithm-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1741/wetneb/explicit_diff_algorithm-v1
Pull-Request: https://github.com/git/git/pull/1741
builtin/merge-file.c | 8 ++++++++
t/t6403-merge-file.sh | 5 +++--
2 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/builtin/merge-file.c b/builtin/merge-file.c
index 1f987334a31..dce2676415e 100644
--- a/builtin/merge-file.c
+++ b/builtin/merge-file.c
@@ -29,6 +29,8 @@ static int label_cb(const struct option *opt, const char *arg, int unset)
return 0;
}
+static int explicit_diff_algorithm = 0;
+
static int set_diff_algorithm(xpparam_t *xpp,
const char *alg)
{
@@ -50,6 +52,8 @@ static int diff_algorithm_cb(const struct option *opt,
return error(_("option diff-algorithm accepts \"myers\", "
"\"minimal\", \"patience\" and \"histogram\""));
+ explicit_diff_algorithm = 1;
+
return 0;
}
@@ -103,6 +107,10 @@ int cmd_merge_file(int argc, const char **argv, const char *prefix)
return error_errno("failed to redirect stderr to /dev/null");
}
+ if (!explicit_diff_algorithm) {
+ warning(_("--diff-algorithm not provided, defaulting to \"myers\". This default will change to \"histogram\" in a future version."));
+ }
+
if (object_id)
setup_git_directory();
diff --git a/t/t6403-merge-file.sh b/t/t6403-merge-file.sh
index fb872c5a113..9d0045be955 100755
--- a/t/t6403-merge-file.sh
+++ b/t/t6403-merge-file.sh
@@ -540,8 +540,9 @@ test_expect_success 'merging C files with "myers" diff algorithm creates some sp
}
EOF
- test_must_fail git merge-file -p --diff3 --diff-algorithm myers ours.c base.c theirs.c >myers_output.c &&
- test_cmp expect.c myers_output.c
+ test_must_fail git merge-file -p --diff3 ours.c base.c theirs.c >myers_output.c 2> err &&
+ test_cmp expect.c myers_output.c &&
+ grep "diff-algorithm not provided" err
'
test_expect_success 'merging C files with "histogram" diff algorithm avoids some spurious conflicts' '
base-commit: 06e570c0dfb2a2deb64d217db78e2ec21672f558
--
gitgitgadget
