Merge branch 'jk/lsan-race-ignore-false-positive'

The code to check LSan results has been simplified and made more
robust.

* jk/lsan-race-ignore-false-positive:
  test-lib: add a few comments to LSan log checking
  test-lib: simplify lsan results check
  test-lib: invert return value of check_test_results_san_file_empty

t/test-lib-functions.sh

@@ -927,7 +927,7 @@ test_expect_success () {
 		test -n "$test_skip_test_preamble" ||
 		say >&3 "expecting success of $TEST_NUMBER.$test_count '$1': $test_body"
 		if test_run_ "$test_body" &&
-		   check_test_results_san_file_empty_
+		   ! check_test_results_san_file_has_entries_
 		then
 			test_ok_ "$1"
 		else

t/test-lib.sh

@@ -1169,20 +1169,20 @@ test_atexit_handler () {
 	teardown_malloc_check
 }
 
-check_test_results_san_file_empty_ () {
-	test -z "$TEST_RESULTS_SAN_FILE" && return 0
+check_test_results_san_file_has_entries_ () {
+	test -z "$TEST_RESULTS_SAN_FILE" && return 1
 
-	# stderr piped to /dev/null because the directory may have
-	# been "rmdir"'d already.
-	! find "$TEST_RESULTS_SAN_DIR" \
-		-type f \
-		-name "$TEST_RESULTS_SAN_FILE_PFX.*" 2>/dev/null |
-	xargs grep ^DEDUP_TOKEN |
+	# Lines marked with DEDUP_TOKEN show unique leaks. We only care that we
+	# found at least one.
+	#
+	# But also suppress any false positives caused by bugs or races in the
+	# sanitizer itself.
+	grep -s ^DEDUP_TOKEN "$TEST_RESULTS_SAN_FILE".* |
 	grep -qv sanitizer::GetThreadStackTopAndBottom
 }
 
 check_test_results_san_file_ () {
-	if check_test_results_san_file_empty_
+	if ! check_test_results_san_file_has_entries_
 	then
 		return
 	fi &&