On Wed, Jun 19, 2019 at 05:21:59PM -0400, Jeff King wrote: > On Fri, Jun 14, 2019 at 03:56:54PM -0700, Emily Shaffer wrote: > > > > Ah, I see. I don't consider "|" to indicate an exclusion to the point > > > that the options are rejected. Only that you wouldn't want to use both, > > > because one counteracts the other. So every "--no-foo" is mutually > > > exclusive with "--foo" in the sense that one override the other. But the > > > outcome is "last one wins", and not "whoops, we cannot figure out what > > > you meant". And that's what the original: > > > > > > --abbrev=<n> | --no-abbrev > > > > > > before your patch was trying to say (and I suspect there are many other > > > cases of "|" with this kind of last-one-wins behavior). > > > > For what it's worth, in this case it's not last-one-wins - --no-abbrev > > always wins: > > Ah, thanks for pointing that; I hadn't noticed. That _is_ unlike most of > the rest of Git. I'm tempted to say it's a bug and should be fixed, but > I worry slightly that it could have an unexpected effect. > > > I think a good solution here is to go and add --abbrev-commit=<n> > > without breaking support for --abbrev=<n>; I'm a little more worried > > about changing --no-abbrev to last-one-wins but I'll take a crack at it > > and see what the test suite says. While I'm at it, I'll check for > > last-one-wins with multiple instances of --abbrev[-commit]=<n>. > > I think --abbrev-commit=<n> sounds safe enough, though I worry it may > get a bit complicated because we'd presumably want to fall back to the > <n> from --abbrev=<n>. I'll see how your patch turns out. :) > > I like the idea of changing --no-abbrev to last-one-wins, as above, but > the test suite may not give us that much confidence. These kinds of > cases are often not well-covered, and we're really worried about the > wider world of random scripts people have grown over the last 10 years. > Of course if the test suite does break horribly that might give us extra > caution, but I'm not sure "the test suite does not break" gives us much > confidence. I think at that point, based on what I've seen on the list, there's a tendency to include a config option to enable the new behavior. And I think that might pass the tipping point of "wasted effort" for me. The change isn't really enabling anything that was impossible before (last-one-wins is handy, but it's legacy public behavior now for --abbrev). So I'm kind of starting to lean towards doing nothing at all. It's a lot of work, for a not-very-functional change, which needs to be specially configured to even happen... So maybe I'll save my time and work on actual bugs instead. :) > > > Having done so, I'll also change the documentation here in rev-list to: > > --abbrev-commit[=<n>] [--abbrev=<n>] | --no-abbrev > > Yeah, that makes sense. > > -Peff Thanks for the input, all. I think I'll drop this. - Emily
