Perly Git: make sure we do test the freshly built one.

We could BEGIN { push @INC, '@@INSTLIBDIR@@'; } but that is not
a good idea for normal execution.  The would prevent a
workaround for a user who is trying to override an old, faulty
Git.pm installed on the system path with a newer version
installed under $HOME/.

Signed-off-by: Junio C Hamano <junkio@cox.net>

git-fmt-merge-msg.perl

@@ -5,7 +5,11 @@
 # Read .git/FETCH_HEAD and make a human readable merge message
 # by grouping branches and tags together to form a single line.
 
-BEGIN { unshift @INC, '@@INSTLIBDIR@@'; }
+BEGIN {
+	unless (exists $ENV{'RUNNING_GIT_TESTS'}) {
+		unshift @INC, '@@INSTLIBDIR@@';
+	}
+}
 use strict;
 use Git;
 use Error qw(:try);

git-mv.perl

@@ -6,7 +6,11 @@
 # This file is licensed under the GPL v2, or a later version
 # at the discretion of Linus Torvalds.
 
-BEGIN { unshift @INC, '@@INSTLIBDIR@@'; }
+BEGIN {
+	unless (exists $ENV{'RUNNING_GIT_TESTS'}) {
+		unshift @INC, '@@INSTLIBDIR@@';
+	}
+}
 use warnings;
 use strict;
 use Getopt::Std;

t/test-lib.sh

@@ -206,8 +206,9 @@ PYTHON=`sed -e '1{
 	PYTHONPATH=$(pwd)/../compat
 	export PYTHONPATH
 }
+RUNNING_GIT_TESTS=YesWeAre
 PERL5LIB=$(pwd)/../perl/blib/lib:$(pwd)/../perl/blib/arch/auto/Git
-export PERL5LIB
+export PERL5LIB RUNNING_GIT_TESTS
 test -d ../templates/blt || {
 	error "You haven't built things yet, have you?"
 }