Re: [PATCH v2 7/7] pack-objects: use mru list when iterating over packs

> Here's the code to do the cycle-breaking. Aside from the "hacky" bit,
> it's quite simple.  I added a new state enum to object_entry to handle
> the graph traversal. Since it only needs 2 bits, I _assume_ a compiler
> can fit it in with the bitfields above (or at the very least give it its
> own single byte so we just use what would otherwise be struct padding).
> But I didn't check; if it turns out not to be the case we can easily
> emulate it with two bitfields.  The write_object() check abuses the
> "idx.offset" field to keep the same state, but we could convert it to
> use these flags if we care.

> @@ -1516,6 +1577,13 @@ static void get_object_details(void)
>  			entry->no_try_delta = 1;
>  	}
>  
> +	/*
> +	 * This must happen in a second pass, since we rely on the delta
> +	 * information for the whole list being completed.
> +	 */
> +	for (i = 0; i < to_pack.nr_objects; i++)
> +		break_delta_cycles(&to_pack.objects[i]);
> +
>  	free(sorted_by_offset);
>  }