On Thu, Oct 26, 2023 at 11:56:57AM +0200, Patrick Steinhardt wrote: > The git-show-ref(1) command has three different modes, of which one is > implicit and the other two can be chosen explicitly by passing a flag. > But while these modes are standalone and cause us to execute completely > separate code paths, we gladly accept the case where a user asks for > both `--exclude-existing` and `--verify` at the same time even though it > is not obvious what will happen. Spoiler: we ignore `--verify` and > execute the `--exclude-existing` mode. > > Let's explicitly detect this invalid usage and die in case both modes > were requested. > > Signed-off-by: Patrick Steinhardt <ps@xxxxxx> > --- > builtin/show-ref.c | 4 ++++ > t/t1403-show-ref.sh | 5 +++++ > 2 files changed, 9 insertions(+) > > diff --git a/builtin/show-ref.c b/builtin/show-ref.c > index 87bc45d2d13..1768aef77b3 100644 > --- a/builtin/show-ref.c > +++ b/builtin/show-ref.c > @@ -271,6 +271,10 @@ int cmd_show_ref(int argc, const char **argv, const char *prefix) > argc = parse_options(argc, argv, prefix, show_ref_options, > show_ref_usage, 0); > > + if ((!!exclude_existing_opts.enabled + !!verify) > 1) > + die(_("only one of '%s' or '%s' can be given"), > + "--exclude-existing", "--verify"); > + This is technically correct, but I was surprised to see it written this way instead of if (exclude_existing_opts.enabled && verify) die(...); I don't think it's a big deal either way, I was just curious why you chose one over the other. > +test_expect_success 'show-ref sub-modes are mutually exclusive' ' > + test_must_fail git show-ref --verify --exclude-existing 2>err && > + grep "only one of ${SQ}--exclude-existing${SQ} or ${SQ}--verify${SQ} can be given" err > +' grepping is fine here, but since you have the exact error message, it may be worth switching to test_cmp. Thanks, Taylor