On 2024-10-16 10:57, Patrick Steinhardt wrote:
> Given that we do set `log.abbrev` I think we should be hitting code
> paths in git-shortlog(1) that use it. `git shortlog --format=%h` for
> example would use `log.abbrev`, wouldn't it? It would be nice to
> figure out whether this can be made to misbehave based on which object
> hash we have in the input.
I dove into the code again and now I'm fairly sure custom formatting is
only ever done when in a repository. shortlog_output() itself, called at
the end of cmd_shortlog(), doesn't do any formatting, only possibly
wrapping the lines already present in the shortlog struct.
That struct is filled either by read_from_stdin() or get_from_rev(). The
latter is only ever called when in a repository:
> if (!nongit && !rev.pending.nr && isatty(0))
> add_head_to_pending(&rev);
> if (rev.pending.nr == 0) {
> if (isatty(0))
> fprintf(stderr, _("(reading log message from standard input)\n"));
> read_from_stdin(&log);
> }
> else
> get_from_rev(&rev, &log);
get_from_rev() handles formatting through shortlog_add_commit(),
directly formatting the commit into the oneline buffer that is later
added to the shortlog struct:
> if (!log->summary) {
> if (log->user_format)
> pretty_print_commit(&ctx, commit, &oneline);
> else
> repo_format_commit_message(the_repository, commit,
> "%s", &oneline, &ctx);
> }
> oneline_str = oneline.len ? oneline.buf : "<none>";
>
> insert_records_from_trailers(log, &dups, commit, &ctx, oneline_str);
> insert_records_from_format(log, &dups, commit, &ctx, oneline_str);
read_from_stdin(), in comparison, skips all lines from stdin not
matching either "Author: " or "Commit: ", and then adds only the
author/committer name and the subject to its log:
> const char *v;
> if (!skip_prefix(ident.buf, match[0], &v) &&
> !skip_prefix(ident.buf, match[1], &v))
> continue;
> while (strbuf_getline_lf(&oneline, stdin) != EOF &&
> oneline.len)
> ; /* discard headers */
> while (strbuf_getline_lf(&oneline, stdin) != EOF &&
> !oneline.len)
> ; /* discard blanks */
>
> strbuf_reset(&mapped_ident);
> if (parse_ident(log, &mapped_ident, v) < 0)
> continue;
>
> insert_one_record(log, mapped_ident.buf, oneline.buf);
So whilst we parse all the relevant options like --abbrev and --format,
we take a shortcut through read_from_stdin() and never get to apply a
custom format. Commit hashes from stdin are discarded.
I'm not sure a test case for different hash algorithms would test
anything meaningful here, unless the plan in the future is to have
git-shortlog(1) support formatting when reading from stdin.
--
Wolf
