test-lib: GIT_TEST_SANITIZE_LEAK_LOG enabled by default

As we currently describe in t/README, it can happen that:

    Some tests run "git" (or "test-tool" etc.) without properly checking
    the exit code, or git will invoke itself and fail to ferry the
    abort() exit code to the original caller.

Therefore, GIT_TEST_SANITIZE_LEAK_LOG=true is needed to be set to
capture all memory leaks triggered by our tests.

It seems unnecessary to force users to remember this option, as
forgetting it could lead to missed memory leaks.

We could solve the problem by making it "true" by default, but that
might suggest we think "false" makes sense, which isn't the case.

Therefore, the best approach is to remove the option entirely while
maintaining the capability to detect memory leaks in blind spots of our
tests.

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

Author: rjusto

ci/lib.sh

@@ -374,7 +374,6 @@ linux-musl)
 linux-leaks|linux-reftable-leaks)
 	export SANITIZE=leak
 	export GIT_TEST_PASSING_SANITIZE_LEAK=true
-	export GIT_TEST_SANITIZE_LEAK_LOG=true
 	;;
 linux-asan-ubsan)
 	export SANITIZE=address,undefined

t/README

@@ -382,33 +382,9 @@ 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".
 
-GIT_TEST_SANITIZE_LEAK_LOG=true will log memory leaks to
-"test-results/$TEST_NAME.leak/trace.*" files. The logs include a
-"dedup_token" (see +"ASAN_OPTIONS=help=1 ./git") and other options to
-make logs +machine-readable.
-
-With GIT_TEST_SANITIZE_LEAK_LOG=true we'll look at the leak logs
-before exiting and exit on failure if the logs showed that we had a
-memory leak, even if the test itself would have otherwise passed. This
-allows us to catch e.g. missing &&-chaining. This is especially useful
-when combined with "GIT_TEST_PASSING_SANITIZE_LEAK", see below.
-
 GIT_TEST_PASSING_SANITIZE_LEAK=check when combined with "--immediate"
 will run to completion faster, and result in the same failing
-tests. The only practical reason to run
-GIT_TEST_PASSING_SANITIZE_LEAK=check without "--immediate" is to
-combine it with "GIT_TEST_SANITIZE_LEAK_LOG=true". If we stop at the
-first failing test case our leak logs won't show subsequent leaks we
-might have run into.
-
-GIT_TEST_PASSING_SANITIZE_LEAK=(true|check) will not catch all memory
-leaks unless combined with GIT_TEST_SANITIZE_LEAK_LOG=true. Some tests
-run "git" (or "test-tool" etc.) without properly checking the exit
-code, or git will invoke itself and fail to ferry the abort() exit
-code to the original caller. When the two modes are combined we'll
-look at the "test-results/$TEST_NAME.leak/trace.*" files at the end of
-the test run to see if had memory leaks which the test itself didn't
-catch.
+tests.
 
 GIT_TEST_PROTOCOL_VERSION=<n>, when set, makes 'protocol.version'
 default to n.

t/test-lib.sh

@@ -1271,10 +1271,10 @@ check_test_results_san_file_ () {
 		invert_exit_code=t
 	elif test "$test_failure" = 0
 	then
-		say "With GIT_TEST_SANITIZE_LEAK_LOG=true our logs revealed a memory leak, exit non-zero!" &&
+		say "Our logs revealed a memory leak, exit non-zero!" &&
 		invert_exit_code=t
 	else
-		say "With GIT_TEST_SANITIZE_LEAK_LOG=true our logs revealed a memory leak..."
+		say "Our logs revealed a memory leak..."
 	fi
 }
 
@@ -1578,33 +1578,28 @@ then
 		test_done
 	fi
 
-	if test_bool_env GIT_TEST_SANITIZE_LEAK_LOG false
+	if ! mkdir -p "$TEST_RESULTS_SAN_DIR"
 	then
-		if ! mkdir -p "$TEST_RESULTS_SAN_DIR"
-		then
-			BAIL_OUT "cannot create $TEST_RESULTS_SAN_DIR"
-		fi &&
-		TEST_RESULTS_SAN_FILE="$TEST_RESULTS_SAN_DIR/$TEST_RESULTS_SAN_FILE_PFX"
+		BAIL_OUT "cannot create $TEST_RESULTS_SAN_DIR"
+	fi &&
+	TEST_RESULTS_SAN_FILE="$TEST_RESULTS_SAN_DIR/$TEST_RESULTS_SAN_FILE_PFX"
 
-		# In case "test-results" is left over from a previous
-		# run: Only report if new leaks show up.
-		TEST_RESULTS_SAN_DIR_NR_LEAKS_STARTUP=$(nr_san_dir_leaks_)
+	# In case "test-results" is left over from a previous
+	# run: Only report if new leaks show up.
+	TEST_RESULTS_SAN_DIR_NR_LEAKS_STARTUP=$(nr_san_dir_leaks_)
 
-		# Don't litter *.leak dirs if there was nothing to report
-		test_atexit "rmdir \"$TEST_RESULTS_SAN_DIR\" 2>/dev/null || :"
+	# Don't litter *.leak dirs if there was nothing to report
+	test_atexit "rmdir \"$TEST_RESULTS_SAN_DIR\" 2>/dev/null || :"
+
+	prepend_var LSAN_OPTIONS : dedup_token_length=9999
+	prepend_var LSAN_OPTIONS : log_exe_name=1
+	prepend_var LSAN_OPTIONS : log_path=\"$TEST_RESULTS_SAN_FILE\"
+	export LSAN_OPTIONS
 
-		prepend_var LSAN_OPTIONS : dedup_token_length=9999
-		prepend_var LSAN_OPTIONS : log_exe_name=1
-		prepend_var LSAN_OPTIONS : log_path=\"$TEST_RESULTS_SAN_FILE\"
-		export LSAN_OPTIONS
-	fi
 elif test "$GIT_TEST_PASSING_SANITIZE_LEAK" = "check" ||
      test_bool_env GIT_TEST_PASSING_SANITIZE_LEAK false
 then
 	BAIL_OUT_ENV_NEEDS_SANITIZE_LEAK "GIT_TEST_PASSING_SANITIZE_LEAK=true"
-elif test_bool_env GIT_TEST_SANITIZE_LEAK_LOG false
-then
-	BAIL_OUT_ENV_NEEDS_SANITIZE_LEAK "GIT_TEST_SANITIZE_LEAK_LOG=true"
 fi
 
 if test "${GIT_TEST_CHAIN_LINT:-1}" != 0 &&