On Thu, Mar 26, 2020 at 03:27:19PM +0100, Johannes Schindelin wrote: > > OK. This looks good, even if I cannot help feel that my earlier patch > > was perfectly sufficient. ;) > > The mistake is all mine. I had totally missed that you turned GPG into a > lazy prereq. So I had my patch finalized already before you pointed my > nose at that fact. > > Sorry about that. No problem. And I hope my review didn't sound too passive-aggressive with the "well, in MY version we did this...". I focused on the differences because those were the parts that were new (and therefore interesting) to me. But I don't think any of them are too important either way. > > I have a slight preference for "return 1" here. The "exit 1" works > > because test_lazy_prereq puts us in an implicit subshell. But I think > > this sets a bad example for people writing regular tests, where there is > > no such subshell (and "return 1" is the only correct way to do it). > > There are two reasons why I did not use `return` here: > > - To me, prereq code is very distinct from writing tests. Just like we do > not &&-chain all the shell functions that live outside of tests, I don't > want to &&-chain all the prereq code. > > The point of the tests' commands is not to fail. The point of prereq's > code is to fail if the prereq is not met. My only concern is whether people cargo-culting will notice the distinction. But it's probably not a big deal. > - Since this code is outside of a function, `return` felt like the wrong > semantic concept to me. And indeed, I see this (rather scary) part in > Bash's documentation of `return` (I did not even bother to look at the > POSIX semantics, it scared me so much): > > The return status is non-zero if `return` is supplied a non-numeric > argument, or is used outside a function and not during execution of > a script by `.` or `source`. > > So: the `1` is totally ignored in this context. That alone is reason > enough for me to completely avoid it, and use `exit` instead. I agree the portability rules there are scary, but none of that applies because we _are_ in a function: test_eval_inner_(). This behavior is intentional and due to a7c58f280a (test: cope better with use of return for errors, 2011-08-08). I thought we specifically advertised this feature in t/README, but I can't seem to find it. So my perspective was the opposite of yours: "return" is the officially sanctioned way to exit early from a test snippet, and "exit" only happens to work because of the undocumented fact that lazy prereqs happen in a subshell. But it turns out neither was documented. :) > > In mine I put the test_have_prereq outside the lazy prereq. > > That makes it essentially a non-lazy prereq. > > > I don't think it really matters either way (when we later ask if GPGSM > > is set, there is no difference between nobody having defined it, and > > having a lazy definition that said "no"). > > The difference is when running a test with `--run=<n>` where `<n>` refers > to a test case that requires neither GPG nor GPGSM or RFC1991. My version > will not evaluate the GPG prereq, yours still will. Yes. Part of the reason I kept mine as it was is because it matched the original behavior better (and I was really only using a lazy prereq because we didn't have a non-lazy version). But there's really no reason _not_ to be lazy, so as long as it isn't breaking anything I think that's a better way forward. (And if it is breaking something, that something should be fixed). -Peff
