test-lib: add a few comments to LSan log checking

Commit b119a68 (test-lib: ignore leaks in the sanitizer's thread code, 2025-01-01) added code to suppress a false positive in the leak checker. But if you're just reading the code, the obscure grep call is a bit of a head-scratcher. Let's add a brief comment explaining what's going on (and anybody digging further can find this commit or that one for all the details). Signed-off-by: Jeff King <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget · Jan 7, 2025 · 164a251 · 164a251
1 parent b9a9df9
commit 164a251
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/t/test-lib.sh b/t/test-lib.sh
@@ -1172,6 +1172,11 @@ test_atexit_handler () {
 check_test_results_san_file_has_entries_ () {
 	test -z "$TEST_RESULTS_SAN_FILE" && return 1
 
+	# 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
 }