Re: [PATCH 3/7] refactor argv_array into generic code

> diff --git a/argv-array.c b/argv-array.c
> new file mode 100644
> index 0000000..a50507a
> --- /dev/null
> +++ b/argv-array.c
> @@ -0,0 +1,52 @@
> +#include "cache.h"
> +#include "argv-array.h"
> +#include "strbuf.h"
> +
> +static const char *empty_argv_storage = NULL;
> +const char **empty_argv = &empty_argv_storage;
> +
> +void argv_array_init(struct argv_array *array)
> +{
> +       array->argv = empty_argv;
> +       array->argc = 0;
> +       array->alloc = 0;
> +}
> +
> +static void argv_array_push_nodup(struct argv_array *array, const char *value)
> +{
> +       if (array->argv == empty_argv)
> +               array->argv = NULL;
> +
> +       ALLOC_GROW(array->argv, array->argc + 2, array->alloc);
> +       array->argv[array->argc++] = value;
> +       array->argv[array->argc] = NULL;
> +}
> +
> +void argv_array_push(struct argv_array *array, const char *value)
> +{
> +       argv_array_push_nodup(array, xstrdup(value));
> +}
> +
> +void argv_array_pushf(struct argv_array *array, const char *fmt, ...)
> +{
> +       va_list ap;
> +       struct strbuf v = STRBUF_INIT;
> +
> +       va_start(ap, fmt);
> +       strbuf_vaddf(&v, fmt, ap);
> +       va_end(ap);
> +
> +       argv_array_push_nodup(array, strbuf_detach(&v, NULL));
> +}