test-lib: Use $TEST_DIRECTORY or $GIT_BUILD_DIR instead of $(pwd) and ../

Change the redundant calls to $(pwd) to use $TEST_DIRECTORY
instead. None of these were being executed after we cd'd somewhere
else so they weren't actually needed.

This also makes it easier to add support for overriding the test
library location and run tests in a different directory than t/.

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

t/test-lib.sh

@@ -793,14 +793,14 @@ else # normal case, use ../bin-wrappers only unless $with_dashes:
 		PATH="$TEST_DIRECTORY/..:$PATH"
 	fi
 fi
-GIT_BUILD_DIR=$(pwd)/..
-GIT_TEMPLATE_DIR=$(pwd)/../templates/blt
+GIT_BUILD_DIR="$TEST_DIRECTORY"/..
+GIT_TEMPLATE_DIR="$TEST_DIRECTORY"/../templates/blt
 unset GIT_CONFIG
 GIT_CONFIG_NOSYSTEM=1
 GIT_CONFIG_NOGLOBAL=1
 export PATH GIT_EXEC_PATH GIT_TEMPLATE_DIR GIT_CONFIG_NOSYSTEM GIT_CONFIG_NOGLOBAL
 
-. ../GIT-BUILD-OPTIONS
+. "$GIT_BUILD_DIR"/GIT-BUILD-OPTIONS
 
 if test -z "$GIT_TEST_CMP"
 then
@@ -812,22 +812,22 @@ then
 	fi
 fi
 
-GITPERLLIB=$(pwd)/../perl/blib/lib:$(pwd)/../perl/blib/arch/auto/Git
+GITPERLLIB="$TEST_DIRECTORY"/../perl/blib/lib:"$TEST_DIRECTORY"/../perl/blib/arch/auto/Git
 export GITPERLLIB
-test -d ../templates/blt || {
+test -d "$TEST_DIRECTORY"/../templates/blt || {
 	error "You haven't built things yet, have you?"
 }
 
 if test -z "$GIT_TEST_INSTALLED" && test -z "$NO_PYTHON"
 then
-	GITPYTHONLIB="$(pwd)/../git_remote_helpers/build/lib"
+	GITPYTHONLIB="$TEST_DIRECTORY/../git_remote_helpers/build/lib"
 	export GITPYTHONLIB
-	test -d ../git_remote_helpers/build || {
+	test -d "$TEST_DIRECTORY"/../git_remote_helpers/build || {
 		error "You haven't built git_remote_helpers yet, have you?"
 	}
 fi
 
-if ! test -x ../test-chmtime; then
+if ! test -x "$TEST_DIRECTORY"/../test-chmtime; then
 	echo >&2 'You need to build test-chmtime:'
 	echo >&2 'Run "make test-chmtime" in the source (toplevel) directory'
 	exit 1