Eric Wong <e@xxxxxxxxx> writes:
> Junio C Hamano <gitster@xxxxxxxxx> wrote:
>> Eric Wong <e@xxxxxxxxx> writes:
>> > +# n.b. consider using Git.pm
>> > +sub use_fsync {
>> > + if (!defined($_use_fsync)) {
>> > + my $x = $ENV{GIT_TEST_FSYNC};
>> > + if (defined $x) {
>>
>> I would have expected to see "exists $ENV{GIT_TEST_FSYNC}", but I
>> guess there is no way to place in %ENV anyway, so it would be OK.
>
> Was that meant to say: "no way to place `undef' in %ENV anyway"?
Yes. Nothing the external callers of a Perl script does by futzing
the environment with setenv(3) and unsetenv(3) can make undef appear
as a value in $ENV{SomeKey}, so defined $ENV{V} and exists $ENV{V}
are equivalent.
I still prefer "exists $ENV{V}", which I think conveys the intent of
the check better, i.e. "we do this iff the environment variable X is
there".
> If so, `undef' can actually be in Perl's %ENV, though it appears
> to get coerced into "" (empty string) when spawning processes.
Yes, but you are talking about the opposite direction, what Perl can
do to %ENV to affect processes it spawns, which is not what I meant.
> Leaving GIT_CONFIG set was actually causing "git config" to
> exit(1) since git-cvsserver sets GIT_CONFIG and the GIT_CONFIG
> file doesn't have a test.fsync setting. This is the current
> behavior, I think it's a weird quirk, but intended behavior of
> git-config.
Ah, sorry, I misread the variable. GIT_CONFIG was the thing that
says "read from this file and nowhere else"; we do want to disable
it locally for "-c var=val" to take effect.
> # this assumes you don't have foo.bar set in your ~/.gitconfig :>
> $ GIT_CONFIG=$HOME/.gitconfig git -c foo.bar=0 config --type=bool foo.bar
> $ echo $?
> 1
>
>> > + my $v = ::safe_pipe_capture('git', '-c', "test.fsync=$x",
>> > + qw(config --type=bool test.fsync));
>>
>> THis is an interesting idiom.
>
> Heh, I just thought of it before sending my original. I was
> going to use a regexp originally (in git-svn, too), but didn't
> want to get into corner cases such as hex and +/- prefixes).
And this I think is the best way to do so ;-)
