[PATCH v2 2/3] format-patch: add an option to suppress commit hash
Oftentimes, patches created by git format-patch will be stored in version control or compared with diff. In these cases, two otherwise identical patches can have different commit hashes, leading to diff noise. Teach git format-patch a --zero-commit option that instead produces an all-zero hash to avoid this diff noise.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
---
Documentation/git-format-patch.txt | 4 ++++
builtin/log.c | 5 +++++
log-tree.c | 3 ++-
revision.h | 1 +
t/t4014-format-patch.sh | 6 ++++++
5 files changed, 18 insertions(+), 1 deletion(-)
Show changes to 5 files +18 −1
Documentation/git-format-patch.txt, builtin/log.c, log-tree.c, revision.h, t/t4014-format-patch.sh
diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index 40356491..e3cdaeb9 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -256,6 +256,10 @@ you can use `--suffix=-patch` to get `0001-description-of-my-change-patch`.
using this option cannot be applied properly, but they are
still useful for code review.
+--zero-commit::
+ Output an all-zero hash in each patch's From header instead
+ of the hash of the commit.
+
--root::
Treat the revision argument as a <revision range>, even if it
is just a single commit (that would normally be treated as a
diff --git a/builtin/log.c b/builtin/log.c
index 069bd3a9..e00cea75 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -1196,6 +1196,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
int cover_letter = -1;
int boundary_count = 0;
int no_binary_diff = 0;
+ int zero_commit = 0;
struct commit *origin = NULL;
const char *in_reply_to = NULL;
struct patch_ids ids;
@@ -1236,6 +1237,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
PARSE_OPT_NOARG | PARSE_OPT_NONEG, keep_callback },
OPT_BOOL(0, "no-binary", &no_binary_diff,
N_("don't output binary diffs")),
+ OPT_BOOL(0, "zero-commit", &zero_commit,
+ N_("output all-zero hash in From header")),
OPT_BOOL(0, "ignore-if-in-upstream", &ignore_if_in_upstream,
N_("don't include a patch matching a commit upstream")),
{ OPTION_SET_INT, 'p', "no-stat", &use_patch_format, NULL,
@@ -1380,6 +1383,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
/* Always generate a patch */
rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
+ rev.zero_commit = zero_commit;
+
if (!DIFF_OPT_TST(&rev.diffopt, TEXT) && !no_binary_diff)
DIFF_OPT_SET(&rev.diffopt, BINARY);
diff --git a/log-tree.c b/log-tree.c
index 35e78017..f70a30e1 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -342,7 +342,8 @@ void log_write_email_headers(struct rev_info *opt, struct commit *commit,
{
const char *subject = NULL;
const char *extra_headers = opt->extra_headers;
- const char *name = oid_to_hex(&commit->object.oid);
+ const char *name = oid_to_hex(opt->zero_commit ?
+ &null_oid : &commit->object.oid);
*need_8bit_cte_p = 0; /* unknown */
if (opt->total > 0) {
diff --git a/revision.h b/revision.h
index 5bc96868..23857c0e 100644
--- a/revision.h
+++ b/revision.h
@@ -135,6 +135,7 @@ struct rev_info {
pretty_given:1,
abbrev_commit:1,
abbrev_commit_given:1,
+ zero_commit:1,
use_terminator:1,
missing_newline:1,
date_mode_explicit:1,
diff --git a/t/t4014-format-patch.sh b/t/t4014-format-patch.sh
index 890db117..b740e3da 100755
--- a/t/t4014-format-patch.sh
+++ b/t/t4014-format-patch.sh
@@ -1431,4 +1431,10 @@ test_expect_success 'cover letter auto user override' '
test_line_count = 2 list
'
+test_expect_success 'format-patch --zero-commit' '
+ git format-patch --zero-commit --stdout v2..v1 >patch2 &&
+ cnt=$(egrep "^From 0{40} Mon Sep 17 00:00:00 2001" patch2 | wc -l) &&
+ test $cnt = 3
+'
+
test_done
brian m. carlson
