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>

2 files changed, 3 insertions, 2 deletions

diff --git a/contrib/examples/git-svnimport.perl b/contrib/examples/git-svnimport.perl
index 4576c4a862..ead4c04d3f 100755
--- a/contrib/examples/git-svnimport.perl
+++ b/contrib/examples/git-svnimport.perl
@@ -1,4 +1,4 @@
-#!/usr/bin/perl -w
+#!/usr/bin/perl
 
 # This tool is copyright (c) 2005, Matthias Urlichs.
 # It is released under the Gnu Public License, version 2.
diff --git a/contrib/fast-import/import-directories.perl b/contrib/fast-import/import-directories.perl
index 3a5da4ab00..7f3afa5ac4 100755
--- a/contrib/fast-import/import-directories.perl
+++ b/contrib/fast-import/import-directories.perl
@@ -1,4 +1,4 @@
-#!/usr/bin/perl -w
+#!/usr/bin/perl
 #
 # Copyright 2008-2009 Peter Krefting <peter@softwolves.pp.se>
 #
@@ -140,6 +140,7 @@ by whitespace or other characters.
 
 # Globals
 use strict;
+use warnings;
 use integer;
 my $crlfmode = 0;
 my @revs;