Stefan Monnier writes: > >> I suppose also info-look might check a derived-mode-parent if a mode >> doesn't have its own setup. That might pick up more things with less >> effort in each mode. > > Oh, yes, that would be a better change. Patch welcome. It took a while but I made the couple of lines below. I considered having the lookup bits such as info-lookup->mode-value do their lookups under a parent mode if the given mode has nothing. But I think there are too many complications from that. Some calls are asking if there's anything before adding and thus don't want a fallback. The caching bits probably would want to cache against the actual name rather than any derived child name. And behaviour would subtly change after a derived mode has loaded and thus gained a `derived-mode-parent' property. A nicer default `info-lookup-mode' should do only good, and it won't affect anything which explicitly selects an info-lookup-mode itself. 2013-02-16 Kevin Ryde * info-look.el (info-lookup-select-mode): If major-mode has no info-lookup-alist entry then search up derived-mode-parent. This means a define-derived-mode uses its parent's info-look setups if it has none of its own. Helps `makefile-gmake-mode' and friends automatically use their parent `makefile-mode' instead of prompting for a mode.