Re: [PATCH v2 1/2] pathspec: allow querying for attributes

[Jonathan Tan <jonathantanmy@google.com>]

Thanks - I don't think I have any more comments on this patch set after 
these.

On 03/10/2017 10:59 AM, Brandon Williams wrote:
> diff --git a/pathspec.c b/pathspec.c
> index b961f00c8..7cd5f6e3d 100644
> --- a/pathspec.c
> +++ b/pathspec.c
> @@ -87,6 +89,74 @@ static void prefix_magic(struct strbuf *sb, int prefixlen, unsigned magic)
>  	strbuf_addf(sb, ",prefix:%d)", prefixlen);
>  }
>
> +static void parse_pathspec_attr_match(struct pathspec_item *item, const char *value)
> +{
> +	struct string_list_item *si;
> +	struct string_list list = STRING_LIST_INIT_DUP;
> +
> +	if (item->attr_check)
> +		die(_("Only one 'attr:' specification is allowed."));
> +
> +	if (!value || !*value)
> +		die(_("attr spec must not be empty"));
> +
> +	string_list_split(&list, value, ' ', -1);
> +	string_list_remove_empty_items(&list, 0);
> +
> +	item->attr_check = attr_check_alloc();
> +	ALLOC_GROW(item->attr_match,
> +		   list.nr,
> +		   item->attr_match_alloc);

If item->attr_match always starts empty, then I think an xmalloc or 
xcalloc suffices (and we don't need item->attr_match_alloc anymore).

We should probably also check item->attr_match above - that is, `if 
(item->attr_check || item->attr_match)`.

> +
> +	for_each_string_list_item(si, &list) {
> +		size_t attr_len;
> +		char *attr_name;
> +		const struct git_attr *a;
> +
> +		int j = item->attr_match_nr++;
> +		const char *attr = si->string;
> +		struct attr_match *am = &item->attr_match[j];
> +
> +		switch (*attr) {
> +		case '!':
> +			am->match_mode = MATCH_UNSPECIFIED;
> +			attr++;
> +			attr_len = strlen(attr);
> +			break;
> +		case '-':
> +			am->match_mode = MATCH_UNSET;
> +			attr++;
> +			attr_len = strlen(attr);
> +			break;
> +		default:
> +			attr_len = strcspn(attr, "=");
> +			if (attr[attr_len] != '=')
> +				am->match_mode = MATCH_SET;
> +			else {
> +				am->match_mode = MATCH_VALUE;
> +				am->value = xstrdup(&attr[attr_len + 1]);
> +				if (strchr(am->value, '\\'))
> +					die(_("attr spec values must not contain backslashes"));
> +			}
> +			break;
> +		}
> +
> +		attr_name = xmemdupz(attr, attr_len);
> +		a = git_attr(attr_name);
> +		if (!a)
> +			die(_("invalid attribute name %s"), attr_name);
> +
> +		attr_check_append(item->attr_check, a);
> +
> +		free(attr_name);
> +	}
> +
> +	if (item->attr_check->nr != item->attr_match_nr)
> +		die("BUG: should have same number of entries");

I think such postcondition checks are usually not worth it, but others 
might differ.

> +
> +	string_list_clear(&list, 0);
> +}
> +
>  static inline int get_literal_global(void)
>  {
>  	static int literal = -1;