perl: use "use warnings" instead of -w

Change the Perl scripts to turn on lexical warnings instead of setting
the global $^W variable via the -w switch.

The -w sets warnings for all code that interpreter runs, while "use
warnings" is lexically scoped. The former is probably not what the
authors wanted.

As an auxiliary benefit it's now possible to build Git with:

    PERL_PATH='/usr/bin/env perl'

Which would previously result in failures, since "#!/usr/bin/env perl -w"
doesn't work as a shebang.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/git-cvsexportcommit.perl b/git-cvsexportcommit.perl
index 9a8188bba7..39a426e067 100755
--- a/git-cvsexportcommit.perl
+++ b/git-cvsexportcommit.perl
@@ -1,7 +1,8 @@
-#!/usr/bin/perl -w
+#!/usr/bin/perl
 
 use 5.008;
 use strict;
+use warnings;
 use Getopt::Std;
 use File::Temp qw(tempdir);
 use Data::Dumper;