Subject: Re: [PATCH 3/5] commit-graph: use parse_options_concat()

From: Taylor Blau <[email-masked]>
Date: Sat, 18 Sep 2021 00:30:49 -0400

On Fri, Sep 17, 2021 at 06:03:58PM -0400, Jeff King wrote:
> > I'm inclined to think that '--progress' should rather be removed from
> > the common 'git commit-graph' options; luckily it's not too late,
> > because it hasn't been released yet.
>
> I wasn't following this series closely, but having seen your fix below,
> I'm inclined to agree with you. Just because we _can_ allow options
> before or after sub-commands does not necessarily make it a good idea.
>
I agree. Suppose we had a "git commit-graph remove" sub-command that
removed the commit-graph file (ignoring that there are probably better
hypothetical examples than this ;)). It's not obvious what --progress
means in the context of that mode.

Here's a patch that does what you and Gábor are suggesting as an
alternative. Unfortunately, we can't do the same for the
multi-pack-index command, since the analogous change there is 60ca94769c
(builtin/multi-pack-index.c: split sub-commands, 2021-03-30), which was
released in 2.32.

Anyway, as promised:

--- 8< ---

Subject: [PATCH] builtin/commit-graph.c: don't accept common --[no-]progress

In 84e4484f12 (commit-graph: use parse_options_concat(), 2021-08-23) we
unified common options of commit-graph's subcommands into a single
"common_opts" array.

But 84e4484f12 introduced a behavior change which is to accept the
"--[no-]progress" option before any sub-commands, e.g.,

    git commit-graph --progress write ...

Prior to that commit, the above would error out with "unknown option".

There are two issues with this behavior change. First is that the
top-level --[no-]progress is not always respected. This is because
isatty(2) is performed in the sub-commands, which unconditionally
overwrites any --[no-]progress that was given at the top-level.

But the second issue is that the existing sub-commands of commit-graph
only happen to both have a sensible interpretation of what `--progress`
or `--no-progress` means. If we ever added a sub-command which didn't
have a notion of progress, we would be forced to ignore the top-level
`--[no-]progress` altogether.

Since we haven't released a version of Git that supports --[no-]progress
as a top-level option for `git commit-graph`, let's remove it.

Suggested-by: SZEDER Gábor <[email-masked]>
Signed-off-by: Taylor Blau <[email-masked]>
---
 builtin/commit-graph.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index 21fc6e934b..067587a0fd 100644
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -50,8 +50,6 @@ static struct option common_opts[] = {
 	OPT_STRING(0, "object-dir", &opts.obj_dir,
 		   N_("dir"),
 		   N_("the object directory to store the graph")),
-	OPT_BOOL(0, "progress", &opts.progress,
-		 N_("force progress reporting")),
 	OPT_END()
 };

@@ -95,6 +93,8 @@ static int graph_verify(int argc, const char **argv)
 	static struct option builtin_commit_graph_verify_options[] = {
 		OPT_BOOL(0, "shallow", &opts.shallow,
 			 N_("if the commit-graph is split, only verify the tip file")),
+		OPT_BOOL(0, "progress", &opts.progress,
+			 N_("force progress reporting")),
 		OPT_END(),
 	};
 	struct option *options = add_common_options(builtin_commit_graph_verify_options);
@@ -246,6 +246,8 @@ static int graph_write(int argc, const char **argv)
 		OPT_CALLBACK_F(0, "max-new-filters", &write_opts.max_new_filters,
 			NULL, N_("maximum number of changed-path Bloom filters to compute"),
 			0, write_option_max_new_filters),
+		OPT_BOOL(0, "progress", &opts.progress,
+			 N_("force progress reporting")),
 		OPT_END(),
 	};
 	struct option *options = add_common_options(builtin_commit_graph_write_options);
--
2.33.0.96.g73915697e6