Re: [PATCH 1/1] Use correct /dev/null for UNIX and Windows

From: Chris Webster <chris@webstech.net>
Date: Oct 31, 2018, 05:41 UTC
Message-ID: <CAGT1KpWC_+=u7fCzQJsU8d_gSQzE5rsx46cTXogvaRPHZ1iiHw@mail.gmail.com>
In-Reply-To: <CAGT1KpWoGD0xgTrC-+X1WqY_M=2arYbs4ZX6Nnj-zHK6mgu+nw@mail.gmail.com>

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On Tue, Oct 30, 2018 at 10:20 PM Chris Webster <chris@webstech.net> wrote:

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>
> On Tue, Oct 30, 2018 at 9:54 PM Junio C Hamano <gitster@pobox.com> wrote:
>>
>> "chris via GitGitGadget" <gitgitgadget@gmail.com> writes:
>>
>> > From: chris <chris@webstech.net>
>> >
>> > Use File::Spec->devnull() for output redirection to avoid messages
>> > when Windows version of Perl is first in path.  The message 'The
>>
>> Dscho, "Windows version of Perl is first in path" somehow feels
>> contradicting with what one of the topics I saw from you were trying
>> to enforce (or, at least, "set as the supported configuration").
>>
>> I am guessing that the Perl you are building and shipping with Git
>> for Windows would yield what the shell that ends up running the
>> scriptlet `git config --get-color $key` prefers when asked for
>> File::Spec->devnull(), and nothing will break with this patch even
>> if that is "/dev/null", but I thought I'd double check.
>>
>> Thanks.
>>

This problem originally showed up in the https://github.com/so-fancy/diff-so-fancy project, which has a copy of DiffHighlight.pm. That project allows diffsofancy (perl) to be run from the command line without requiring the bash environment ((well , sort of) including the associated perl).

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>
>> > system cannot find the path specified.' is displayed each time git is
>> > run to get colors.
>> >
>> > Signed-off-by: Chris. Webster <chris@webstech.net>
>> > ---
>> >  contrib/diff-highlight/DiffHighlight.pm | 7 ++++++-
>> >  1 file changed, 6 insertions(+), 1 deletion(-)
>> >
>> > diff --git a/contrib/diff-highlight/DiffHighlight.pm b/contrib/diff-highlight/DiffHighlight.pm
>> > index 536754583..7440aa1c4 100644
>> > --- a/contrib/diff-highlight/DiffHighlight.pm
>> > +++ b/contrib/diff-highlight/DiffHighlight.pm
>> > @@ -4,6 +4,11 @@ use 5.008;
>> >  use warnings FATAL => 'all';
>> >  use strict;
>> >
>> > +# Use the correct value for both UNIX and Windows (/dev/null vs nul)
>> > +use File::Spec;
>> > +
>> > +my $NULL = File::Spec->devnull();
>> > +
>> >  # Highlight by reversing foreground and background. You could do
>> >  # other things like bold or underline if you prefer.
>> >  my @OLD_HIGHLIGHT = (
>> > @@ -134,7 +139,7 @@ sub highlight_stdin {
>> >  # fallback, which means we will work even if git can't be run.
>> >  sub color_config {
>> >       my ($key, $default) = @_;
>> > -     my $s = `git config --get-color $key 2>/dev/null`;
>> > +     my $s = `git config --get-color $key 2>$NULL`;
>> >       return length($s) ? $s : $default;
>> >  }