test-lib: Make the test_external_* functions TAP-aware

diff --git a/t/t3411-rebase-preserve-around-merges.sh b/t/t3411-rebase-preserve-around-merges.sh
index 6533505218a51db369d03357603c2ad1926ce448..14a23cd8726fbb33df480133ed0466177916b7fb 100755 (executable)
--- a/t/t3411-rebase-preserve-around-merges.sh
+++ b/t/t3411-rebase-preserve-around-merges.sh
@@ -10,7 +10,7 @@ a merge to before the merge.
 '
 . ./test-lib.sh
 
-. ../lib-rebase.sh
+. "$TEST_DIRECTORY"/lib-rebase.sh
 
 set_fake_editor