On Mon, Jul 23, 2018 at 12:12 PM Duy Nguyen <pclouds@xxxxxxxxx> wrote: > On Sun, Jul 22, 2018 at 11:57 AM Eric Sunshine <sunshine@xxxxxxxxxxxxxx> wrote: > > @@ -215,6 +215,7 @@ struct rev_info { > > /* interdiff */ > > const struct object_id *idiff_oid1; > > const struct object_id *idiff_oid2; > > + const char *idiff_title; > > I feel we're abusing struct rev_info a bit for this since this > interdiff thing is very builtin/log.c's business and not at all > related to rev walk. Is it possible (and easy) to just pass > idfff_title from cmd_format_patch to make_cover_letter()? If it's a > lot of code, then I guess we can just leave it here. As originally implemented, this information was passed directly to make_cover_letter(), however, as you discovered in your review of patch 6/14[1], which makes it possible to embed an interdiff in the commentary section of a lone patch, 'struct rev_info' is the only way to pass this information down that deeply in the patch-generation process. So, yes, this pretty much needs to use 'struct rev_info', even if that need doesn't exist at this early step in the series. [1]: https://public-inbox.org/git/CACsJy8Aw6R8-3kDfhCqunXziajCg9O_1WrEYc4rfKa+-=m1D5g@xxxxxxxxxxxxxx/