Esme Povirk (@madewokherd) commented about dlls/comdlg32/navbar.c:
INT next_w = w + crumb1->full_w; crumb1->current_w = crumb1->full_w; if (next_w > max_crumbs_w) break;
I think the "at least N in the list" check might be simpler as part of this loop. If `crumbs_visible_n < 2`, you can just give it the remaining space here and then break out of the loop.