test-lib: check for TEST_PASSES_SANITIZE_LEAK

TEST_PASSES_SANITIZE_LEAK must be set before sourcing test-lib.sh, as we
say in t/README:

   GIT_TEST_PASSING_SANITIZE_LEAK=true skips those tests that haven't
   declared themselves as leak-free by setting
   "TEST_PASSES_SANITIZE_LEAK=true" before sourcing "test-lib.sh". This
   test mode is used by the "linux-leaks" CI target.

   GIT_TEST_PASSING_SANITIZE_LEAK=check checks that our
   "TEST_PASSES_SANITIZE_LEAK=true" markings are current. Rather than
   skipping those tests that haven't set "TEST_PASSES_SANITIZE_LEAK=true"
   before sourcing "test-lib.sh" this mode runs them with
   "--invert-exit-code". This is used to check that there's a one-to-one
   mapping between "TEST_PASSES_SANITIZE_LEAK=true" and those tests that
   pass under "SANITIZE=leak". This is especially useful when testing a
   series that fixes various memory leaks with "git rebase -x".

In a recent commit we fixed a test where it was set after sourcing
test-lib.sh, leading to confusing results.

To prevent future oversights, let's add a simple check to ensure the
value for TEST_PASSES_SANITIZE_LEAK remains unchanged at test_done().

Signed-off-by: Rubén Justo <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: rjusto

t/test-lib.sh

@@ -1297,6 +1297,11 @@ test_done () {
 		EOF
 	fi
 
+	if test -z "$passes_sanitize_leak" && test_bool_env TEST_PASSES_SANITIZE_LEAK false
+	then
+		BAIL_OUT "Please, set TEST_PASSES_SANITIZE_LEAK before sourcing test-lib.sh"
+	fi
+
 	if test "$test_fixed" != 0
 	then
 		say_color error "# $test_fixed known breakage(s) vanished; please update test(s)"