Re: [PATCH v4 4/4] pack-bitmap.c: trace bitmap ignore logs when midx-bitmap is found

[Jeff King <peff@peff.net>]

On Mon, Nov 21, 2022 at 08:16:15PM +0800, Teng Long wrote:

> From: Jeff King <peff@peff.net>
> 
> We retained pack bitmaps as a quick recovery mechanism while
> test-deploying midx bitmaps. This is an internal mechanism, and we
> want to expose this rule externally through trace2 so that end users,
> repo-maintainers, and debuggers know what is happening in the process.

Re-reading this outside the context of the earlier thread, I think "this
rule" is a little vague. Maybe:

  When we find a midx bitmap, we do not bother checking for pack
  bitmaps, since we can use only one. But since we will warn of unused
  bitmaps via trace2, let's continue looking for pack bitmaps when
  tracing is enabled.

> @@ -559,11 +557,20 @@ static int open_midx_bitmap(struct repository *r,
>  static int open_bitmap(struct repository *r,
>  		       struct bitmap_index *bitmap_git)
>  {
> +	int found = 0;
> +
>  	assert(!bitmap_git->map);
>  
> -	if (!open_midx_bitmap(r, bitmap_git))
> -		return 0;
> -	return open_pack_bitmap(r, bitmap_git);
> +	found = !open_midx_bitmap(r, bitmap_git);

I think we can drop the initialization of "found = 0"; that value is
unused, since we'll always assign to it (I think my initial attempt had
setting it to 1 inside the conditional).

It's not hurting anything functionally, but it makes the code slightly
more confusing to read.

-Peff