diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index 6821441..a5f145e 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -265,6 +265,21 @@ you can use `--suffix=-patch` to get `0001-description-of-my-change-patch`.
Output an all-zero hash in each patch's From header instead
of the hash of the commit.
+--base=<commit>::
+ Record the base tree information to identify the whole tree
+ the patch series applies to. For example, the patch submitter
+ has a commit history of this shape:
+
+ ---P---X---Y---Z---A---B---C
+
+ where "P" is the well-known public commit (e.g. one in Linus's tree),
+ "X", "Y", "Z" are prerequisite patches in flight, and "A", "B", "C"
+ are the work being sent out, the submitter would say "format-patch
+ --base=P -3 C" (or variants thereof, e.g. with "--cover" or using
+ "Z..C" instead of "-3 C" to specify the range), and the identifiers
+ for P, X, Y, Z are appended at the end of the _first_ message (either
+ the cover letter or the first patch in the series).
+
--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 0d738d6..d3804b3 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -1185,6 +1185,88 @@ static int from_callback(const struct option *opt, const char *arg, int unset)
return 0;
}
+struct base_tree_info {
+ struct object_id base_commit;
+ int nr_patch_id, alloc_patch_id;
+ struct object_id *patch_id;
+};
+
+static void prepare_bases(struct base_tree_info *bases,
+ const char *base_commit,
+ struct commit *prerequisite_head)
+{
+ struct commit *base = NULL, *commit;
+ struct rev_info revs;
+ struct diff_options diffopt;
+ struct object_id *patch_id;
+ unsigned char sha1[20];
+ int pos = 0;
+
+ if (!prerequisite_head)
+ return;
+ base = lookup_commit_reference_by_name(base_commit);
+ if (!base)
+ die(_("Unknown commit %s"), base_commit);
+ oidcpy(&bases->base_commit, &base->object.oid);
+
+ if (base == prerequisite_head)
+ return;
+
+ if (!in_merge_bases(base, prerequisite_head))
+ die(_("base commit should be the ancestor of revs you specified"));
+
+ init_revisions(&revs, NULL);
+ revs.max_parents = 1;
+
+ base->object.flags |= UNINTERESTING;
+ add_pending_object(&revs, &base->object, "base");
+ prerequisite_head->object.flags |= 0;
+ add_pending_object(&revs, &prerequisite_head->object, "prerequisite-head");
+
+ diff_setup(&diffopt);
+ DIFF_OPT_SET(&diffopt, RECURSIVE);
+ diff_setup_done(&diffopt);
+
+ if (prepare_revision_walk(&revs))
+ die(_("revision walk setup failed"));
+ /*
+ * Traverse the commits list between base and prerequisite head,
+ * get the patch ids and stuff them in bases structure.
+ */
+ while ((commit = get_revision(&revs)) != NULL) {
+ if (commit_patch_id(commit, &diffopt, sha1))
+ return;
+ ALLOC_GROW(bases->patch_id, bases->nr_patch_id + 1, bases->alloc_patch_id);
+ patch_id = bases->patch_id + pos;
+ hashcpy(patch_id->hash, sha1);
+ pos++;
+ bases->nr_patch_id++;
+ }
+}
+
+static void print_bases(struct base_tree_info *bases)
+{
+ int i;
+
+ /* Only do this once, either for the cover or for the first one */
+ if (is_null_oid(&bases->base_commit))
+ return;
+
+ printf("** base-commit-info **\n");
+
+ /* Show the base commit */
+ printf("base-commit: %s\n", oid_to_hex(&bases->base_commit));
+
+ /* Show the prerequisite patches */
+ for (i = 0; i < bases->nr_patch_id; i++)
+ printf("prerequisite-patch-id: %s\n", oid_to_hex(&bases->patch_id[i]));
+
+ free(bases->patch_id);
+ bases->nr_patch_id = 0;
+ bases->alloc_patch_id = 0;
+ oidclr(&bases->base_commit);
+}
+
int cmd_format_patch(int argc, const char **argv, const char *prefix)
{
struct commit *commit;@@ -1209,6 +1291,9 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
int reroll_count = -1;
char *branch_name = NULL;
char *from = NULL;
+ char *base_commit = NULL;
+ struct base_tree_info bases;
+
const struct option builtin_format_patch_options[] = {
{ OPTION_CALLBACK, 'n', "numbered", &numbered, NULL,
N_("use [PATCH n/m] even with a single patch"),@@ -1271,6 +1356,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
PARSE_OPT_OPTARG, thread_callback },
OPT_STRING(0, "signature", &signature, N_("signature"),
N_("add a signature")),
+ OPT_STRING(0, "base", &base_commit, N_("base-commit"),
+ N_("add prerequisite tree info to the patch series")),
OPT_FILENAME(0, "signature-file", &signature_file,
N_("add a signature from a file")),
OPT__QUIET(&quiet, N_("don't print the patch filenames")),@@ -1507,6 +1594,15 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
signature = strbuf_detach(&buf, NULL);
}
+ if (base_commit) {
+ struct commit *prerequisite_head = NULL;
+ if (list[nr - 1]->parents)
+ prerequisite_head = list[nr - 1]->parents->item;
+ memset(&bases, 0, sizeof(bases));
+ reset_revision_walk();
+ prepare_bases(&bases, base_commit, prerequisite_head);
+ }
+
if (in_reply_to || thread || cover_letter)
rev.ref_message_ids = xcalloc(1, sizeof(struct string_list));
if (in_reply_to) {@@ -1520,6 +1616,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
gen_message_id(&rev, "cover");
make_cover_letter(&rev, use_stdout,
origin, nr, list, branch_name, quiet);
+ print_bases(&bases);
total++;
start_number--;
}
@@ -1585,6 +1682,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
rev.mime_boundary);
else
print_signature();
+ print_bases(&bases);
}
if (!use_stdout)
fclose(stdout);
--
2.8.0.rc4.4.ga41a987