Re: [PATCH v3] blame: report correct number of lines in progress when using ranges

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

On Tue, Apr 05 2022, Edmundo Carmona Antoranz wrote:

Hint: use --in-reply-to on re-rolls, this is in reply to v2 here:
https://lore.kernel.org/git/20220404182129.33992-1-eantoranz@gmail.com/

Also the --range-diff option to git-format-patch is really helpful,
it'll make a diff between v2 and this v3 and attach it after "--".

Anyway...

> Note: Shamelessly copied show_cr from t0500-progress-display.sh
> Signed-off-by: Edmundo Carmona Antoranz <eantoranz@gmail.com>

Formatting: \n before the Signed-off-by.

> ---
>  builtin/blame.c     |  6 ++++-
>  t/annotate-tests.sh | 53 +++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 58 insertions(+), 1 deletion(-)
>
> diff --git a/builtin/blame.c b/builtin/blame.c
> index 8d15b68afc..e33372c56b 100644
> --- a/builtin/blame.c
> +++ b/builtin/blame.c
> @@ -898,6 +898,7 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
>  	unsigned int range_i;
>  	long anchor;
>  	const int hexsz = the_hash_algo->hexsz;
> +	long num_lines = 0;
>  
>  	setup_default_color_by_age();
>  	git_config(git_blame_config, &output_option);
> @@ -1129,7 +1130,10 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
>  	for (range_i = ranges.nr; range_i > 0; --range_i) {
>  		const struct range *r = &ranges.ranges[range_i - 1];
>  		ent = blame_entry_prepend(ent, r->start, r->end, o);
> +		num_lines += (r->end - r->start);
>  	}
> +	if (!num_lines)
> +		num_lines = sb.num_lines;
>  
>  	o->suspects = ent;
>  	prio_queue_put(&sb.commits, o->commit);
> @@ -1158,7 +1162,7 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
>  	sb.found_guilty_entry = &found_guilty_entry;
>  	sb.found_guilty_entry_data = &pi;
>  	if (show_progress)
> -		pi.progress = start_delayed_progress(_("Blaming lines"), sb.num_lines);
> +		pi.progress = start_delayed_progress(_("Blaming lines"), num_lines);
>  
>  	assign_blame(&sb, opt);
>  
> diff --git a/t/annotate-tests.sh b/t/annotate-tests.sh
> index 09e86f9ba0..90932e304b 100644
> --- a/t/annotate-tests.sh
> +++ b/t/annotate-tests.sh
> @@ -12,6 +12,10 @@ else
>    }
>  fi
>  
> +show_cr () {
> +	tr '\015' Q | sed -e "s/Q/<CR>\\$LF/g"
> +}
> +
>  check_count () {
>  	head= &&
>  	file='file' &&
> @@ -604,3 +608,52 @@ test_expect_success 'blame -L X,-N (non-numeric N)' '
>  test_expect_success 'blame -L ,^/RE/' '
>  	test_must_fail $PROG -L1,^/99/ file
>  '
> +
> +test_expect_success 'blame progress on a full file' '
> +	cat >expect <<-\EOF &&
> +	Blaming lines:  10% (1/10)<CR>
> +	Blaming lines:  50% (5/10)<CR>
> +	Blaming lines:  60% (6/10)<CR>
> +	Blaming lines:  90% (9/10)<CR>
> +	Blaming lines: 100% (10/10)<CR>
> +	Blaming lines: 100% (10/10), done.
> +	EOF
> +
> +	GIT_PROGRESS_DELAY=0 \
> +	git blame --progress hello.c 2>stderr &&
> +
> +	show_cr <stderr >actual &&
> +	test_cmp expect actual
> +'
> +
> +test_expect_success 'blame progress on a single range' '
> +	cat >expect <<-\EOF &&
> +	Blaming lines:  25% (1/4)<CR>
> +	Blaming lines:  75% (3/4)<CR>
> +	Blaming lines: 100% (4/4)<CR>
> +	Blaming lines: 100% (4/4), done.
> +	EOF
> +
> +	GIT_PROGRESS_DELAY=0 \
> +	git blame --progress -L 3,6 hello.c 2>stderr &&
> +
> +	show_cr <stderr >actual &&
> +	test_cmp expect actual
> +'
> +
> +test_expect_success 'blame progress on multiple ranges' '
> +	cat >expect <<-\EOF &&
> +	Blaming lines:  42% (3/7)<CR>
> +	Blaming lines:  57% (4/7)<CR>
> +	Blaming lines:  85% (6/7)<CR>
> +	Blaming lines: 100% (7/7)<CR>
> +	Blaming lines: 100% (7/7), done.
> +	EOF
> +
> +	GIT_PROGRESS_DELAY=0 \
> +	git blame --progress -L 3,6 -L 8,10 hello.c 2>stderr &&
> +
> +	cp stderr /home/antoranz/proyectos/git/git/stderr &&
> +	show_cr <stderr >actual &&
> +	test_cmp expect actual
> +'

We had a small thread that I notice now was off-list in reply to
https://lore.kernel.org/git/220405.86o81flve1.gmgdl@evledraar.gmail.com/. Quoted
below. I assume that was both of our mistakes:

	On Tue, Apr 05 2022, Ævar Arnfjörð Bjarmason wrote:
	
	> On Tue, Apr 05 2022, Edmundo Carmona Antoranz wrote:
	>
	>> On Tue, Apr 5, 2022 at 11:41 AM Ævar Arnfjörð Bjarmason
	>> <avarab@gmail.com> wrote:
	>>>
	>>>
	>>> Let's use test_cmp here instead, as we expect nothing else on stderr,
	>>> and with grep one wonders why it's not ^$ anchored, but just:
	>>>
	>>>     echo "Blaming lines: 100% (6/6), done." >expect &&
	>>>     git blame ... 2>actual &&
	>>>     test_cmp expect actual
	>>>
	>>> is better, both because it's more exhaustive as a test, and because
	>>> it'll give better debug (diff) output on failure than grep will (just no
	>>> output at all).
	>>>
	>>
	>> The problem is that progress output is using CRs to write each line
	>> so, when checking the output, if you tried with ^$ with the last line,
	>> it wouldn't match anyway. I switched to match progress output as a
	>> whole using the same technique that is used in
	>> t0500-progress-display.sh.
	>>
	>> v3 is already out there.
	>
	> Ah yes, I forgot about that. Nevermind

I.e. the test_cmp here is now, given what you mentioned I'd have been
fine with the grep, but stealing the show_cr also works.

I suppose it's also abetter as a targeted fix, since the point of this
patch is specifically to fix a bug where we wouldn't do the right
"steps" in-between with the progress bar, in addition to the end-state
not being correct.

Are the small number of missing steps above expected? E.g. 1-2/7 and 5/7
in the last tets above, ditto the rest?

Mm, yes, looking at assign_blame() in blame.c we'll "skip" some.

So if we ever change that algorithm we'll need to adjust these, but it's
probably good to notice that then, even if the test_cmp here does
implicitly encode a bit of internal implementation details, i.e. when
exactly we update the progress bar.