1 files changed, 115 insertions, 0 deletions
diff --git a/replay.c b/replay.c
new file mode 100644
index 0000000000..58fdc20140
--- /dev/null
+++ b/replay.c
@@ -0,0 +1,115 @@
+#define USE_THE_REPOSITORY_VARIABLE
+
+#include "git-compat-util.h"
+#include "commit.h"
+#include "environment.h"
+#include "gettext.h"
+#include "ident.h"
+#include "object.h"
+#include "object-name.h"
+#include "replay.h"
+#include "tree.h"
+
+static const char *short_commit_name(struct repository *repo,
+				     struct commit *commit)
+{
+	return repo_find_unique_abbrev(repo, &commit->object.oid,
+				       DEFAULT_ABBREV);
+}
+
+static char *get_author(const char *message)
+{
+	size_t len;
+	const char *a;
+
+	a = find_commit_header(message, "author", &len);
+	if (a)
+		return xmemdupz(a, len);
+
+	return NULL;
+}
+
+struct commit *replay_create_commit(struct repository *repo,
+				    struct tree *tree,
+				    struct commit *based_on,
+				    struct commit *parent)
+{
+	struct object_id ret;
+	struct object *obj = NULL;
+	struct commit_list *parents = NULL;
+	char *author;
+	char *sign_commit = NULL; /* FIXME: cli users might want to sign again */
+	struct commit_extra_header *extra = NULL;
+	struct strbuf msg = STRBUF_INIT;
+	const char *out_enc = get_commit_output_encoding();
+	const char *message = repo_logmsg_reencode(repo, based_on,
+						   NULL, out_enc);
+	const char *orig_message = NULL;
+	const char *exclude_gpgsig[] = { "gpgsig", NULL };
+
+	commit_list_insert(parent, &parents);
+	extra = read_commit_extra_headers(based_on, exclude_gpgsig);
+	find_commit_subject(message, &orig_message);
+	strbuf_addstr(&msg, orig_message);
+	author = get_author(message);
+	reset_ident_date();
+	if (commit_tree_extended(msg.buf, msg.len, &tree->object.oid, parents,
+				 &ret, author, NULL, sign_commit, extra)) {
+		error(_("failed to write commit object"));
+		goto out;
+	}
+
+	obj = parse_object(repo, &ret);
+
+out:
+	repo_unuse_commit_buffer(repo, based_on, message);
+	free_commit_extra_headers(extra);
+	free_commit_list(parents);
+	strbuf_release(&msg);
+	free(author);
+	return (struct commit *)obj;
+}
+
+static struct commit *mapped_commit(kh_oid_map_t *replayed_commits,
+				    struct commit *commit,
+				    struct commit *fallback)
+{
+	khint_t pos = kh_get_oid_map(replayed_commits, commit->object.oid);
+	if (pos == kh_end(replayed_commits))
+		return fallback;
+	return kh_value(replayed_commits, pos);
+}
+
+struct commit *replay_pick_regular_commit(struct repository *repo,
+					  struct commit *pickme,
+					  kh_oid_map_t *replayed_commits,
+					  struct commit *onto,
+					  struct merge_options *merge_opt,
+					  struct merge_result *result)
+{
+	struct commit *base, *replayed_base;
+	struct tree *pickme_tree, *base_tree;
+
+	base = pickme->parents->item;
+	replayed_base = mapped_commit(replayed_commits, base, onto);
+
+	result->tree = repo_get_commit_tree(repo, replayed_base);
+	pickme_tree = repo_get_commit_tree(repo, pickme);
+	base_tree = repo_get_commit_tree(repo, base);
+
+	merge_opt->branch1 = short_commit_name(repo, replayed_base);
+	merge_opt->branch2 = short_commit_name(repo, pickme);
+	merge_opt->ancestor = xstrfmt("parent of %s", merge_opt->branch2);
+
+	merge_incore_nonrecursive(merge_opt,
+				  base_tree,
+				  result->tree,
+				  pickme_tree,
+				  result);
+
+	free((char*)merge_opt->ancestor);
+	merge_opt->ancestor = NULL;
+	if (!result->clean)
+		return NULL;
+	return replay_create_commit(repo, result->tree, pickme, replayed_base);
+}