This uses exact metadata when creating the commit object, hopefully
reconstructing the commit with the exact same SHA1.
Note: In order to be forwards compatible with new commit formats we
may want a new helper for creating a commit with the exact metadata
that is present (and then validating the result) as opposed to trying
to parse the metadata and pass it piecewise to commit_tree().
Previous-version: 3120370db888889f32e07a082edb4722db8feef1
Cc: Paul Tan <pyokagan@xxxxxxxxx>
Signed-off-by: Vegard Nossum <vegard.nossum@xxxxxxxxxx>
---
Documentation/git-am.txt | 9 +++-
builtin/am.c | 111 +++++++++++++++++++++++++++++++++++----
t/t4150-am.sh | 30 +++++++++++
3 files changed, 138 insertions(+), 12 deletions(-)
diff --git a/Documentation/git-am.txt b/Documentation/git-am.txt
index fc3b993c33..5b75596aaf 100644
--- a/Documentation/git-am.txt
+++ b/Documentation/git-am.txt
@@ -9,7 +9,7 @@ git-am - Apply a series of patches from a mailbox
SYNOPSIS
--------
[verse]
-'git am' [--signoff] [--keep] [--[no-]keep-cr] [--[no-]utf8]
+'git am' [--[no-]exact] [--signoff] [--keep] [--[no-]keep-cr] [--[no-]utf8]
[--[no-]3way] [--interactive] [--committer-date-is-author-date]
[--ignore-date] [--ignore-space-change | --ignore-whitespace]
[--whitespace=<option>] [-C<n>] [-p<n>] [--directory=<dir>]
@@ -31,6 +31,13 @@ OPTIONS
supply this argument, the command reads from the standard input.
If you supply directories, they will be treated as Maildirs.
+-e::
+--[no-]exact::
+ Reconstruct the exact commit that the patch was generated from,
+ assuming the mail contains complete metadata (i.e. it was generated
+ using `git format-patch --complete`). This is only possible if all
+ the parent commits are available in the repository.
+
-s::
--signoff::
Add a `Signed-off-by:` line to the commit message, using
diff --git a/builtin/am.c b/builtin/am.c
index 4190383bba..c0fc27a2ae 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -118,6 +118,7 @@ struct am_state {
int allow_rerere_autoupdate;
const char *sign_commit;
int rebasing;
+ int exact;
};
/**
@@ -399,6 +400,9 @@ static void am_load(struct am_state *state)
state->rebasing = !!file_exists(am_path(state, "rebasing"));
+ read_state_file(&sb, state, "exact", 1);
+ state->exact = !strcmp(sb.buf, "t");
+
strbuf_release(&sb);
}
@@ -1005,6 +1009,8 @@ static void am_setup(struct am_state *state, enum patch_format patch_format,
else
write_state_text(state, "applying", "");
+ write_state_bool(state, "exact", state->exact);
+
if (!get_oid("HEAD", &curr_head)) {
write_state_text(state, "abort-safety", oid_to_hex(&curr_head));
if (!state->rebasing)
@@ -1548,40 +1554,121 @@ static int fall_back_threeway(const struct am_state *state, const char *index_pa
*/
static void do_commit(const struct am_state *state)
{
+ struct object_id meta_commit = {};
+ struct object_id meta_tree = {};
+
struct object_id tree, parent, commit;
const struct object_id *old_oid;
struct commit_list *parents = NULL;
- const char *reflog_msg, *author;
+ const char *reflog_msg, *author = NULL;
struct strbuf sb = STRBUF_INIT;
+ if (state->exact) {
+ /*
+ * Scan meta file for parents + other data.
+ *
+ * TODO: Pass everything after the "commit ..." line
+ * verbatim to the commit for forwards compatibility
+ * (e.g. so we don't need to know about every type of
+ * commit attribute that may appear in the future).
+ */
+
+ struct strbuf line = STRBUF_INIT;
+ FILE *fp = xfopen(am_path(state, "meta"), "r");
+
+ while (!strbuf_getline_lf(&line, fp)) {
+ const char *rest;
+
+ if (skip_prefix(line.buf, "commit ", &rest)) {
+ if (get_oid_hex(rest, &meta_commit))
+ die("invalid exact metadata (commit)");
+ } else if (skip_prefix(line.buf, "tree ", &rest)) {
+ if (get_oid_hex(rest, &meta_tree))
+ die("invalid exact metadata (tree)");
+ } else if (skip_prefix(line.buf, "parent ", &rest)) {
+ if (get_oid_hex(rest, &parent))
+ die("invalid exact metadata (parent)");
+
+ commit_list_insert(lookup_commit(the_repository, &parent), &parents);
+ } else if (skip_prefix(line.buf, "author ", &rest)) {
+ author = strdup(rest);
+ } else if (skip_prefix(line.buf, "committer ", &rest)) {
+ char *name_copy;
+ char *email;
+ char *email_copy;
+ char *date;
+
+ email = strstr(rest, " <");
+ if (!email)
+ die("invalid exact metadata (committer name)");
+
+ name_copy = xstrndup(rest, email - rest);
+ email += 2;
+ setenv("GIT_COMMITTER_NAME", name_copy, 1);
+ free(name_copy);
+
+ date = strstr(email, "> ");
+ if (!date)
+ die("invalid exact metadata (committer email)");
+
+ email_copy = xstrndup(email, date - email);
+ date += 2;
+ setenv("GIT_COMMITTER_EMAIL", email_copy, 1);
+ free(email_copy);
+
+ setenv("GIT_COMMITTER_DATE", date, 1);
+ } else if (line.len == 0) {
+ break;
+ } else {
+ die("unknown exact metadata: %.*s", (int) line.len, line.buf);
+ }
+ }
+
+ fclose(fp);
+ }
+
if (run_hook_le(NULL, "pre-applypatch", NULL))
exit(1);
if (write_cache_as_tree(&tree, 0, NULL))
die(_("git write-tree failed to write a tree"));
+ if (state->exact && !oideq(&tree, &meta_tree))
+ die("tree mismatch");
+
if (!get_oid_commit("HEAD", &parent)) {
old_oid = &parent;
- commit_list_insert(lookup_commit(the_repository, &parent),
- &parents);
+ if (!state->exact) {
+ commit_list_insert(lookup_commit(the_repository, &parent),
+ &parents);
+ }
} else {
old_oid = NULL;
say(state, stderr, _("applying to an empty history"));
}
- author = fmt_ident(state->author_name, state->author_email,
- WANT_AUTHOR_IDENT,
- state->ignore_date ? NULL : state->author_date,
- IDENT_STRICT);
-
- if (state->committer_date_is_author_date)
- setenv("GIT_COMMITTER_DATE",
- state->ignore_date ? "" : state->author_date, 1);
+ if (state->exact) {
+ /*
+ * Already got author above.
+ */
+ } else {
+ author = fmt_ident(state->author_name, state->author_email,
+ WANT_AUTHOR_IDENT,
+ state->ignore_date ? NULL : state->author_date,
+ IDENT_STRICT);
+
+ if (state->committer_date_is_author_date)
+ setenv("GIT_COMMITTER_DATE",
+ state->ignore_date ? "" : state->author_date, 1);
+ }
if (commit_tree(state->msg, state->msg_len, &tree, parents, &commit,
author, state->sign_commit))
die(_("failed to write commit object"));
+ if (state->exact && !oideq(&commit, &meta_commit))
+ die("sha1 mismatch");
+
reflog_msg = getenv("GIT_REFLOG_ACTION");
if (!reflog_msg)
reflog_msg = "am";
@@ -2182,6 +2269,8 @@ int cmd_am(int argc, const char **argv, const char *prefix)
0, PARSE_OPT_NONEG),
OPT_BOOL('c', "scissors", &state.scissors,
N_("strip everything before a scissors line")),
+ OPT_BOOL('e', "exact", &state.exact,
+ N_("preserve exact metadata, including sha1")),
OPT_PASSTHRU_ARGV(0, "whitespace", &state.git_apply_opts, N_("action"),
N_("pass it through git-apply"),
0),
diff --git a/t/t4150-am.sh b/t/t4150-am.sh
index 4f1e24ecbe..56a0804dcb 100755
--- a/t/t4150-am.sh
+++ b/t/t4150-am.sh
@@ -147,6 +147,7 @@ test_expect_success setup '
git diff-tree --no-commit-id -p second
} >patch1-hg.eml &&
+ git format-patch --stdout --complete first >patch1-complete &&
echo file >file &&
git add file &&
@@ -1061,6 +1062,35 @@ test_expect_success 'am --quit keeps HEAD where it is' '
test_cmp expected actual
'
+test_expect_success 'am --no-exact with metadata succeeds' '
+ rm -fr .git/rebase-apply &&
+ git reset --hard &&
+ git checkout first &&
+ git am --no-exact patch1-complete
+'
+
+test_expect_success 'am --exact without metadata fails' '
+ rm -fr .git/rebase-apply &&
+ git reset --hard &&
+ git checkout first &&
+ test_must_fail git am --exact patch1
+'
+
+test_expect_success 'am --exact with metadata preserves sha1' '
+ rm -fr .git/rebase-apply &&
+ git reset --hard &&
+ git checkout first &&
+ git am --exact patch1-complete &&
+ test_cmp_rev second HEAD
+'
+
+test_expect_success 'am --exact with metadata applied to the wrong tree fails' '
+ rm -fr .git/rebase-apply &&
+ git reset --hard &&
+ git checkout second &&
+ test_must_fail git am --exact patch1-complete
+'
+
test_expect_success 'am and .gitattibutes' '
test_create_repo attributes &&
(
--
commit 429e6ce36ee1fb8e020c76756894bf7e196e7c4e
tree 69ec15522af90642ea38dc761510fd1fa82bdfb2
parent 53da20012e763a65071bfe0a42fbf4968d0e1e49
author Vegard Nossum <vegard.nossum@xxxxxxxxxx> 1571186178 +0200
committer Vegard Nossum <vegard.nossum@xxxxxxxxxx> 1571740256 +0200
--
2.24.0.rc0.3.g4ba423c3c2
