Subject: Re: [PATCH v6 06/11] ref-filter: implement '--merged' and '--no-merged' options

From: Junio C Hamano <[email-masked]>
Date: Mon, 29 Jun 2015 11:03:37 -0700

Karthik Nayak <[email-masked]> writes:

> +static void do_merge_filter(struct ref_filter_cbdata *ref_cbdata)
> +{
> +	struct rev_info revs;
> +	int i, old_nr;
> +	struct ref_filter *filter = ref_cbdata->filter;
> +	struct ref_array *array = ref_cbdata->array;
> +	struct commit **to_clear = xcalloc(sizeof(struct commit *), array->nr);
> +
> +	init_revisions(&revs, NULL);
> +
> +	for (i = 0; i < array->nr; i++) {
> +		struct ref_array_item *item = array->items[i];
> +		add_pending_object(&revs, &item->commit->object, item->refname);
> +		to_clear[i] = item->commit;
> +	}
> +
> +	filter->merge_commit->object.flags |= UNINTERESTING;
> +	add_pending_object(&revs, &filter->merge_commit->object, "");
> +
> +	revs.limited = 1;
> +	if (prepare_revision_walk(&revs))
> +		die(_("revision walk setup failed"));
> +
> +	old_nr = array->nr;
> +	array->nr = 0;
> +
> +	for (i = 0; i < old_nr; i++) {
> +		struct ref_array_item *item = array->items[i];
> +		struct commit *commit = item->commit;
> +
> +		int is_merged = !!(commit->object.flags & UNINTERESTING);
> +
> +		if (is_merged == (filter->merge == REF_FILTER_MERGED_INCLUDE))
> +			array->items[array->nr++] = array->items[i];
> +		else
> +			free_array_item(item);
> +	}
> +
> +	for (i = 0; i < old_nr; i++)
> +		clear_commit_marks(to_clear[i], ALL_REV_FLAGS);
> +	clear_commit_marks(filter->merge_commit, ALL_REV_FLAGS);
> +	free(to_clear);
> +}

Did this come from somewhere else (e.g. tag -l or branch -l)?  If
so, you'd need a note similar to what you added in [02/11] to the
original.

I also have a feeling that compared to an implementation based on
paint_down_to_common(), including is_descendant_of(), this may be
less precise (e.g. it would be confused with clock skew that lasts
more than SLOP commits).  If we are inventing a new helper (as
opposed to moving an existing one), we'd probably be better off
doing a thin wrapper around paint_down_to_common() than calling
revision-walk machinery.