+static int is_fixup(enum todo_command command)
+{
+ return command == TODO_FIXUP || command == TODO_SQUASH;
+}
+
+static int update_squash_messages(enum todo_command command,
+ struct commit *commit, struct replay_opts *opts)
+{
+ struct strbuf buf = STRBUF_INIT;
+ int count, res;
+ const char *message, *body;
+
+ if (file_exists(rebase_path_squash_msg())) {
+ struct strbuf header = STRBUF_INIT;
+ char *eol, *p;
+
+ if (strbuf_read_file(&buf, rebase_path_squash_msg(), 2048) <= 0)
+ return error(_("could not read '%s'"),
+ rebase_path_squash_msg());
+
+ p = buf.buf + 1;
+ eol = strchrnul(buf.buf, '\n');
+ if (buf.buf[0] != comment_line_char ||
+ (p += strcspn(p, "0123456789\n")) == eol)
+ return error(_("unexpected 1st line of squash message:"
+ "\n\n\t%.*s"),
+ (int)(eol - buf.buf), buf.buf);
+ count = strtol(p, NULL, 10);
+
+ if (count < 1)
+ return error(_("invalid 1st line of squash message:\n"
+ "\n\t%.*s"),
+ (int)(eol - buf.buf), buf.buf);
+
+ strbuf_addf(&header, "%c ", comment_line_char);
+ strbuf_addf(&header,
+ _("This is a combination of %d commits."), ++count);
+ strbuf_splice(&buf, 0, eol - buf.buf, header.buf, header.len);
+ strbuf_release(&header);
+ } else {
+ unsigned char head[20];
+ struct commit *head_commit;
+ const char *head_message, *body;
+
+ if (get_sha1("HEAD", head))
+ return error(_("need a HEAD to fixup"));
+ if (!(head_commit = lookup_commit_reference(head)))
+ return error(_("could not read HEAD"));
+ if (!(head_message = get_commit_buffer(head_commit, NULL)))
+ return error(_("could not read HEAD's commit message"));
+
+ find_commit_subject(head_message, &body);
+ if (write_message(body, strlen(body),
+ rebase_path_fixup_msg(), 0)) {
+ unuse_commit_buffer(head_commit, head_message);
+ return error(_("cannot write '%s'"),
+ rebase_path_fixup_msg());
+ }
+
+ count = 2;
+ strbuf_addf(&buf, "%c ", comment_line_char);
+ strbuf_addf(&buf, _("This is a combination of %d commits."),
+ count);
+ strbuf_addf(&buf, "\n%c ", comment_line_char);
+ strbuf_addstr(&buf, _("This is the 1st commit message:"));
+ strbuf_addstr(&buf, "\n\n");
+ strbuf_addstr(&buf, body);
+
+ unuse_commit_buffer(head_commit, head_message);
+ }
+
+ if (!(message = get_commit_buffer(commit, NULL)))
+ return error(_("could not read commit message of %s"),
+ oid_to_hex(&commit->object.oid));
+ find_commit_subject(message, &body);
+
+ if (command == TODO_SQUASH) {
+ unlink(rebase_path_fixup_msg());
+ strbuf_addf(&buf, "\n%c ", comment_line_char);
+ strbuf_addf(&buf, _("This is the commit message #%d:"), count);
+ strbuf_addstr(&buf, "\n\n");
+ strbuf_addstr(&buf, body);
+ } else if (command == TODO_FIXUP) {
+ strbuf_addf(&buf, "\n%c ", comment_line_char);
+ strbuf_addf(&buf, _("The commit message #%d will be skipped:"),
+ count);
+ strbuf_addstr(&buf, "\n\n");
+ strbuf_add_commented_lines(&buf, body, strlen(body));
+ } else
+ return error(_("unknown command: %d"), command);
+ unuse_commit_buffer(commit, message);
+
+ res = write_message(buf.buf, buf.len, rebase_path_squash_msg(), 0);
+ strbuf_release(&buf);
+ return res;
+}
+