Make sure $PERL_PATH is defined when the test suite is run.

Some test scripts run Perl scripts as if they were git-* scripts, and
thus need to use the same perl that will be put in the shebang line of
git*.perl commands. $PERL_PATH therefore needs to be used instead of
a bare "perl".

The tests can fail if another perl is found in $PATH before the one
defined in $PERL_PATH.

Example test failure caused by this: the perl defined in $PERL_PATH has
Error.pm installed, and therefore the Git.pm's Makefile.PL doesn't install
the private copy. The perl from $PATH doesn't have Error.pm installed, and
all git*.perl scripts invoked during the test will fail loading Error.pm.

Makefile patch by Jeff King <peff@peff.net>.

Signed-off-by: Philippe Bruhat (BooK) <book@cpan.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -1626,6 +1626,7 @@ GIT-CFLAGS: .FORCE-GIT-CFLAGS
 # and the first level quoting from the shell that runs "echo".
 GIT-BUILD-OPTIONS: .FORCE-GIT-BUILD-OPTIONS
 	@echo SHELL_PATH=\''$(subst ','\'',$(SHELL_PATH_SQ))'\' >$@
+	@echo PERL_PATH=\''$(subst ','\'',$(PERL_PATH_SQ))'\' >>$@
 	@echo TAR=\''$(subst ','\'',$(subst ','\'',$(TAR)))'\' >>$@
 	@echo NO_CURL=\''$(subst ','\'',$(subst ','\'',$(NO_CURL)))'\' >>$@
 	@echo NO_PERL=\''$(subst ','\'',$(subst ','\'',$(NO_PERL)))'\' >>$@

t/t9400-git-cvsserver-server.sh

@@ -20,7 +20,7 @@ then
     say 'skipping git-cvsserver tests, cvs not found'
     test_done
 fi
-perl -e 'use DBI; use DBD::SQLite' >/dev/null 2>&1 || {
+"$PERL_PATH" -e 'use DBI; use DBD::SQLite' >/dev/null 2>&1 || {
     say 'skipping git-cvsserver tests, Perl SQLite interface unavailable'
     test_done
 }

t/t9401-git-cvsserver-crlf.sh

@@ -57,7 +57,7 @@ then
     say 'skipping git-cvsserver tests, perl not available'
     test_done
 fi
-perl -e 'use DBI; use DBD::SQLite' >/dev/null 2>&1 || {
+"$PERL_PATH" -e 'use DBI; use DBD::SQLite' >/dev/null 2>&1 || {
     say 'skipping git-cvsserver tests, Perl SQLite interface unavailable'
     test_done
 }

t/t9700-perl-git.sh

@@ -11,7 +11,7 @@ if ! test_have_prereq PERL; then
 	test_done
 fi
 
-perl -MTest::More -e 0 2>/dev/null || {
+"$PERL_PATH" -MTest::More -e 0 2>/dev/null || {
 	say "Perl Test::More unavailable, skipping test"
 	test_done
 }
@@ -48,6 +48,6 @@ test_expect_success \
 
 test_external_without_stderr \
     'Perl API' \
-    perl "$TEST_DIRECTORY"/t9700/test.pl
+    "$PERL_PATH" "$TEST_DIRECTORY"/t9700/test.pl
 
 test_done