Hi Johannes,

On 29/05/17 06:59 AM, Johannes Schindelin wrote:

Hi Liam,

On Thu, 25 May 2017, Liam Beguin wrote:

quoted

Johannes Schindelin [off-list ref] writes:

quoted

diff --git a/sequencer.c b/sequencer.c
index 130cc868e51..88819a1a2a9 100644
--- a/sequencer.c
+++ b/sequencer.c

@@ -2388,3 +2388,52 @@ void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
 
 	strbuf_release(&sob);
 }
+
+int sequencer_make_script(int keep_empty, FILE *out,
+		int argc, const char **argv)
+{
+	char *format = NULL;
+	struct pretty_print_context pp = {0};
+	struct strbuf buf = STRBUF_INIT;
+	struct rev_info revs;
+	struct commit *commit;
+
+	init_revisions(&revs, NULL);
+	revs.verbose_header = 1;
+	revs.max_parents = 1;
+	revs.cherry_pick = 1;
+	revs.limited = 1;
+	revs.reverse = 1;
+	revs.right_only = 1;
+	revs.sort_order = REV_SORT_IN_GRAPH_ORDER;
+	revs.topo_order = 1;
+
+	revs.pretty_given = 1;
+	git_config_get_string("rebase.instructionFormat", &format);
+	if (!format || !*format) {
+		free(format);
+		format = xstrdup("%s");
+	}
+	get_commit_format(format, &revs);
+	free(format);
+	pp.fmt = revs.commit_format;
+	pp.output_encoding = get_log_output_encoding();
+
+	if (setup_revisions(argc, argv, &revs, NULL) > 1)
+		return error(_("make_script: unhandled options"));
+
+	if (prepare_revision_walk(&revs) < 0)
+		return error(_("make_script: error preparing revisions"));
+
+	while ((commit = get_revision(&revs))) {
+		strbuf_reset(&buf);
+		if (!keep_empty && is_original_commit_empty(commit))
+			strbuf_addf(&buf, "%c ", comment_line_char);

I've never had to use empty commits before, but while testing this, I
noticed that `git rebase -i --keep-empty` behaves differently if using
the --root option instead of a branch or something like 'HEAD~10'.
I also tested this on v2.13.0 and the behavior is the same.

FWIW the terminology "empty commit" is a pretty poor naming choice. This
is totally not your fault at all. I just wish we had a much more intuitive
name to describe a commit that does not introduce any changes to the tree.

And yes, doing this with --root is a bit of a hack. That's because --root
is a bit of a hack.

I am curious, though, as to the exact differences you experienced. I mean,
it could be buggy behavior that needs to be fixed (independently of this
patch series, of course).

Sorry, reading this I realized that I didn't give any details!
When using --root, --keep-empty has no effect. The empty commits
do not appear in the todo list and they are removed.
Also, when using --root without --keep-empty, the empty commits
do not show up as comments in the list.

Ciao,
Johannes

Liam