Makefile: add Perl runtime prefix support

Broaden the RUNTIME_PREFIX flag to configure Git's Perl scripts to
locate the Git installation's Perl support libraries by resolving
against the script's path, rather than hard-coding that path at
build-time. Hard-coding at build time worked on previous
RUNTIME_PREFIX configurations (i.e., Windows) because the Perl
scripts were run within a virtual filesystem whose paths were
consistent regardless of the location of the actual installation.
This will no longer be the case for non-Windows RUNTIME_PREFIX users.

When enabled, RUNTIME_PREFIX now requires Perl's system paths to be
expressed relative to a common installation directory in the Makefile,
and uses that relationship to locate support files based on the known
starting point of the script being executed, much like RUNTIME_PREFIX
does for the Git binary.

This change enables Git's Perl scripts to work when their Git installation
is relocated or moved to another system, even when they are not in a
virtual filesystem environment.

Signed-off-by: Dan Jacques <dnj@google.com>
Thanks-to: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Thanks-to: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/perl/Git/I18N.pm b/perl/Git/I18N.pm
index dba96fff0a..bfb4fb67a1 100644
--- a/perl/Git/I18N.pm
+++ b/perl/Git/I18N.pm
@@ -18,7 +18,7 @@ our @EXPORT_OK = @EXPORT;
 
 sub __bootstrap_locale_messages {
 	our $TEXTDOMAIN = 'git';
-	our $TEXTDOMAINDIR = $ENV{GIT_TEXTDOMAINDIR} || '@@LOCALEDIR@@';
+	our $TEXTDOMAINDIR ||= $ENV{GIT_TEXTDOMAINDIR} || '@@LOCALEDIR@@';
 
 	require POSIX;
 	POSIX->import(qw(setlocale));