diff --git a/ci/lib.sh b/ci/lib.sh
index f095519f8d..1b0cc2b57d 100755
--- a/ci/lib.sh
+++ b/ci/lib.sh
@@ -276,6 +276,7 @@ linux-musl)
 linux-leaks)
 	export SANITIZE=leak
 	export GIT_TEST_PASSING_SANITIZE_LEAK=true
+	export GIT_TEST_SANITIZE_LEAK_LOG=true
 	;;
 esac
 
diff --git a/contrib/credential/netrc/t-git-credential-netrc.sh b/contrib/credential/netrc/t-git-credential-netrc.sh
index 07227d0228..bf2777308a 100755
--- a/contrib/credential/netrc/t-git-credential-netrc.sh
+++ b/contrib/credential/netrc/t-git-credential-netrc.sh
@@ -3,16 +3,9 @@
 	cd ../../../t
 	test_description='git-credential-netrc'
 	. ./test-lib.sh
+	. "$TEST_DIRECTORY"/lib-perl.sh
 
-	if ! test_have_prereq PERL; then
-		skip_all='skipping perl interface tests, perl not available'
-		test_done
-	fi
-
-	perl -MTest::More -e 0 2>/dev/null || {
-		skip_all="Perl Test::More unavailable, skipping test"
-		test_done
-	}
+	skip_all_if_no_Test_More
 
 	# set up test repository
 
@@ -20,13 +13,10 @@
 		'set up test repository' \
 		'git config --add gpg.program test.git-config-gpg'
 
-	# The external test will outputs its own plan
-	test_external_has_tap=1
-
 	export PERL5LIB="$GITPERLLIB"
-	test_external \
-		'git-credential-netrc' \
+	test_expect_success 'git-credential-netrc' '
 		perl "$GIT_BUILD_DIR"/contrib/credential/netrc/test.pl
+	'
 
 	test_done
 )
diff --git a/contrib/scalar/t/Makefile b/contrib/scalar/t/Makefile
index 01e82e56d1..1ed174a8cf 100644
--- a/contrib/scalar/t/Makefile
+++ b/contrib/scalar/t/Makefile
@@ -42,7 +42,7 @@ $(T):
 	@echo "*** $@ ***"; GIT_CONFIG=.git/config '$(SHELL_PATH_SQ)' $@ $(GIT_TEST_OPTS)
 
 clean-except-prove-cache:
-	$(RM) -r 'trash directory'.* '$(TEST_RESULTS_DIRECTORY_SQ)'
+	$(RM) -r 'trash directory'.*
 	$(RM) -r valgrind/bin
 
 clean: clean-except-prove-cache
diff --git a/contrib/subtree/t/Makefile b/contrib/subtree/t/Makefile
index 276898eb6b..3d278bb0ed 100644
--- a/contrib/subtree/t/Makefile
+++ b/contrib/subtree/t/Makefile
@@ -47,7 +47,7 @@ pre-clean:
 	$(RM) -r '$(TEST_RESULTS_DIRECTORY_SQ)'
 
 clean-except-prove-cache:
-	$(RM) -r 'trash directory'.* '$(TEST_RESULTS_DIRECTORY_SQ)'
+	$(RM) -r 'trash directory'.*
 	$(RM) -r valgrind/bin
 
 clean: clean-except-prove-cache
diff --git a/t/Makefile b/t/Makefile
index 7f56e52f76..1c80c0c79a 100644
--- a/t/Makefile
+++ b/t/Makefile
@@ -62,7 +62,7 @@ pre-clean:
 	$(RM) -r '$(TEST_RESULTS_DIRECTORY_SQ)'
 
 clean-except-prove-cache: clean-chainlint
-	$(RM) -r 'trash directory'.* '$(TEST_RESULTS_DIRECTORY_SQ)'
+	$(RM) -r 'trash directory'.*
 	$(RM) -r valgrind/bin
 
 clean: clean-except-prove-cache
diff --git a/t/README b/t/README
index 4f9981cf5e..2f439f9658 100644
--- a/t/README
+++ b/t/README
@@ -366,12 +366,47 @@ excluded as so much relies on it, but this might change in the future.
 GIT_TEST_SPLIT_INDEX=<boolean> forces split-index mode on the whole
 test suite. Accept any boolean values that are accepted by git-config.
 
-GIT_TEST_PASSING_SANITIZE_LEAK=<boolean> when compiled with
-SANITIZE=leak will run only those tests that have whitelisted
-themselves as passing with no memory leaks. Tests can be whitelisted
-by setting "TEST_PASSES_SANITIZE_LEAK=true" before sourcing
-"test-lib.sh" itself at the top of the test script. This test mode is
-used by the "linux-leaks" CI target.
+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".
+
+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.
 
 GIT_TEST_PROTOCOL_VERSION=<n>, when set, makes 'protocol.version'
 default to n.
@@ -935,32 +970,6 @@ see test-lib-functions.sh for the full list and their options.
 	    test_done
 	fi
 
- - test_external [<prereq>] <message> <external> <script>
-
-   Execute a <script> with an <external> interpreter (like perl). This
-   was added for tests like t9700-perl-git.sh which do most of their
-   work in an external test script.
-
-	test_external \
-	    'GitwebCache::*FileCache*' \
-	    perl "$TEST_DIRECTORY"/t9503/test_cache_interface.pl
-
-   If the test is outputting its own TAP you should set the
-   test_external_has_tap variable somewhere before calling the first
-   test_external* function. See t9700-perl-git.sh for an example.
-
-	# The external test will outputs its own plan
-	test_external_has_tap=1
-
- - test_external_without_stderr [<prereq>] <message> <external> <script>
-
-   Like test_external but fail if there's any output on stderr,
-   instead of checking the exit code.
-
-	test_external_without_stderr \
-	    'Perl API' \
-	    perl "$TEST_DIRECTORY"/t9700/test.pl
-
  - test_expect_code <exit-code> <command>
 
    Run a command and ensure that it exits with the given exit code.
diff --git a/t/lib-perl.sh b/t/lib-perl.sh
new file mode 100644
index 0000000000..d0bf509a16
--- /dev/null
+++ b/t/lib-perl.sh
@@ -0,0 +1,19 @@
+# Copyright (c) 2022 Ævar Arnfjörð Bjarmason
+
+test_lazy_prereq PERL_TEST_MORE '
+	perl -MTest::More -e 0
+'
+
+skip_all_if_no_Test_More () {
+	if ! test_have_prereq PERL
+	then
+		skip_all='skipping perl interface tests, perl not available'
+		test_done
+	fi
+
+	if ! test_have_prereq PERL_TEST_MORE
+	then
+		skip_all="Perl Test::More unavailable, skipping test"
+		test_done
+	fi
+}
diff --git a/t/t0000-basic.sh b/t/t0000-basic.sh
index 17a268ccd1..502b4bcf9e 100755
--- a/t/t0000-basic.sh
+++ b/t/t0000-basic.sh
@@ -578,6 +578,78 @@ test_expect_success 'subtest: --run invalid range end' '
 	EOF_ERR
 '
 
+test_expect_success 'subtest: --invert-exit-code without --immediate' '
+	run_sub_test_lib_test_err full-pass \
+		--invert-exit-code &&
+	check_sub_test_lib_test_err full-pass \
+		<<-\EOF_OUT 3<<-EOF_ERR
+	ok 1 - passing test #1
+	ok 2 - passing test #2
+	ok 3 - passing test #3
+	# passed all 3 test(s)
+	1..3
+	# faking up non-zero exit with --invert-exit-code
+	EOF_OUT
+	EOF_ERR
+'
+
+test_expect_success 'subtest: --invert-exit-code with --immediate: all passed' '
+	run_sub_test_lib_test_err full-pass \
+		--invert-exit-code --immediate &&
+	check_sub_test_lib_test_err full-pass \
+		<<-\EOF_OUT 3<<-EOF_ERR
+	ok 1 - passing test #1
+	ok 2 - passing test #2
+	ok 3 - passing test #3
+	# passed all 3 test(s)
+	1..3
+	# faking up non-zero exit with --invert-exit-code
+	EOF_OUT
+	EOF_ERR
+'
+
+test_expect_success 'subtest: --invert-exit-code without --immediate: partial pass' '
+	run_sub_test_lib_test partial-pass \
+		--invert-exit-code &&
+	check_sub_test_lib_test partial-pass <<-\EOF
+	ok 1 - passing test #1
+	not ok 2 - # TODO induced breakage (--invert-exit-code): failing test #2
+	#	false
+	ok 3 - passing test #3
+	# failed 1 among 3 test(s)
+	1..3
+	# faked up failures as TODO & now exiting with 0 due to --invert-exit-code
+	EOF
+'
+
+test_expect_success 'subtest: --invert-exit-code with --immediate: partial pass' '
+	run_sub_test_lib_test partial-pass \
+		--invert-exit-code --immediate &&
+	check_sub_test_lib_test partial-pass \
+		<<-\EOF_OUT 3<<-EOF_ERR
+	ok 1 - passing test #1
+	not ok 2 - # TODO induced breakage (--invert-exit-code): failing test #2
+	#	false
+	1..2
+	# faked up failures as TODO & now exiting with 0 due to --invert-exit-code
+	EOF_OUT
+	EOF_ERR
+'
+
+test_expect_success 'subtest: --invert-exit-code --immediate: got a failure' '
+	run_sub_test_lib_test partial-pass \
+		--invert-exit-code --immediate &&
+	check_sub_test_lib_test_err partial-pass \
+		<<-\EOF_OUT 3<<-EOF_ERR
+	ok 1 - passing test #1
+	not ok 2 - # TODO induced breakage (--invert-exit-code): failing test #2
+	#	false
+	1..2
+	# faked up failures as TODO & now exiting with 0 due to --invert-exit-code
+	EOF_OUT
+	EOF_ERR
+'
+
 test_expect_success 'subtest: tests respect prerequisites' '
 	write_and_run_sub_test_lib_test prereqs <<-\EOF &&
 
diff --git a/t/t0002-gitfile.sh b/t/t0002-gitfile.sh
index f6356db183..26eaca095a 100755
--- a/t/t0002-gitfile.sh
+++ b/t/t0002-gitfile.sh
@@ -65,7 +65,7 @@ test_expect_success 'check commit-tree' '
 	test_path_is_file "$REAL/objects/$(objpath $SHA)"
 '
 
-test_expect_success !SANITIZE_LEAK 'check rev-list' '
+test_expect_success 'check rev-list' '
 	git update-ref "HEAD" "$SHA" &&
 	git rev-list HEAD >actual &&
 	echo $SHA >expected &&
diff --git a/t/t0004-unwritable.sh b/t/t0004-unwritable.sh
index 2e9d652d82..8114fac73b 100755
--- a/t/t0004-unwritable.sh
+++ b/t/t0004-unwritable.sh
@@ -31,7 +31,7 @@ test_expect_success WRITE_TREE_OUT 'write-tree output on unwritable repository'
 	test_cmp expect out.write-tree
 '
 
-test_expect_success POSIXPERM,SANITY,!SANITIZE_LEAK 'commit should notice unwritable repository' '
+test_expect_success POSIXPERM,SANITY 'commit should notice unwritable repository' '
 	test_when_finished "chmod 775 .git/objects .git/objects/??" &&
 	chmod a-w .git/objects .git/objects/?? &&
 	test_must_fail git commit -m second 2>out.commit
diff --git a/t/t0027-auto-crlf.sh b/t/t0027-auto-crlf.sh
index 7f80f46393..a22e0e1382 100755
--- a/t/t0027-auto-crlf.sh
+++ b/t/t0027-auto-crlf.sh
@@ -2,6 +2,7 @@
 
 test_description='CRLF conversion all combinations'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 compare_files () {
diff --git a/t/t0032-reftable-unittest.sh b/t/t0032-reftable-unittest.sh
index 0ed14971a5..471cb37ac2 100755
--- a/t/t0032-reftable-unittest.sh
+++ b/t/t0032-reftable-unittest.sh
@@ -5,6 +5,7 @@
 
 test_description='reftable unittests'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'unittests' '
diff --git a/t/t0033-safe-directory.sh b/t/t0033-safe-directory.sh
index f4d737dadd..aecb308cf6 100755
--- a/t/t0033-safe-directory.sh
+++ b/t/t0033-safe-directory.sh
@@ -2,6 +2,7 @@
 
 test_description='verify safe.directory checks'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 GIT_TEST_ASSUME_DIFFERENT_OWNER=1
diff --git a/t/t0050-filesystem.sh b/t/t0050-filesystem.sh
index 5c9dc90d0b..325eb1c3cd 100755
--- a/t/t0050-filesystem.sh
+++ b/t/t0050-filesystem.sh
@@ -5,6 +5,7 @@ test_description='Various filesystem issues'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 auml=$(printf '\303\244')
diff --git a/t/t0095-bloom.sh b/t/t0095-bloom.sh
index daeb4a5e3e..b567383eb8 100755
--- a/t/t0095-bloom.sh
+++ b/t/t0095-bloom.sh
@@ -1,6 +1,8 @@
 #!/bin/sh
 
 test_description='Testing the various Bloom filter computations in bloom.c'
+
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'compute unseeded murmur3 hash for empty string' '
diff --git a/t/t0202-gettext-perl.sh b/t/t0202-gettext-perl.sh
index df2ea34932..5a6f28051b 100755
--- a/t/t0202-gettext-perl.sh
+++ b/t/t0202-gettext-perl.sh
@@ -7,22 +7,12 @@ test_description='Perl gettext interface (Git::I18N)'
 
 TEST_PASSES_SANITIZE_LEAK=true
 . ./lib-gettext.sh
+. "$TEST_DIRECTORY"/lib-perl.sh
+skip_all_if_no_Test_More
 
-if ! test_have_prereq PERL; then
-	skip_all='skipping perl interface tests, perl not available'
-	test_done
-fi
-
-perl -MTest::More -e 0 2>/dev/null || {
-	skip_all="Perl Test::More unavailable, skipping test"
-	test_done
-}
-
-# The external test will outputs its own plan
-test_external_has_tap=1
-
-test_external_without_stderr \
-    'Perl Git::I18N API' \
-    perl "$TEST_DIRECTORY"/t0202/test.pl
+test_expect_success 'run t0202/test.pl to test Git::I18N.pm' '
+	"$PERL_PATH" "$TEST_DIRECTORY"/t0202/test.pl 2>stderr &&
+	test_must_be_empty stderr
+'
 
 test_done
diff --git a/t/t1405-main-ref-store.sh b/t/t1405-main-ref-store.sh
index 51f8291628..e4627cf1b6 100755
--- a/t/t1405-main-ref-store.sh
+++ b/t/t1405-main-ref-store.sh
@@ -5,6 +5,7 @@ test_description='test main ref store api'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 RUN="test-tool ref-store main"
diff --git a/t/t1407-worktree-ref-store.sh b/t/t1407-worktree-ref-store.sh
index ad8006c813..05b1881c59 100755
--- a/t/t1407-worktree-ref-store.sh
+++ b/t/t1407-worktree-ref-store.sh
@@ -5,6 +5,7 @@ test_description='test worktree ref store api'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 RWT="test-tool ref-store worktree:wt"
diff --git a/t/t1418-reflog-exists.sh b/t/t1418-reflog-exists.sh
index d51ecd5e92..2268bca3c1 100755
--- a/t/t1418-reflog-exists.sh
+++ b/t/t1418-reflog-exists.sh
@@ -4,6 +4,7 @@ test_description='Test reflog display routines'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'setup' '
diff --git a/t/t1503-rev-parse-verify.sh b/t/t1503-rev-parse-verify.sh
index ba43168d12..bc136833c1 100755
--- a/t/t1503-rev-parse-verify.sh
+++ b/t/t1503-rev-parse-verify.sh
@@ -132,7 +132,7 @@ test_expect_success 'use --default' '
 	test_must_fail git rev-parse --verify --default bar
 '
 
-test_expect_success !SANITIZE_LEAK 'main@{n} for various n' '
+test_expect_success 'main@{n} for various n' '
 	git reflog >out &&
 	N=$(wc -l <out) &&
 	Nm1=$(($N-1)) &&
diff --git a/t/t1701-racy-split-index.sh b/t/t1701-racy-split-index.sh
index 5dc221ef38..d8fa489998 100755
--- a/t/t1701-racy-split-index.sh
+++ b/t/t1701-racy-split-index.sh
@@ -5,6 +5,7 @@
 
 test_description='racy split index'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'setup' '
diff --git a/t/t2006-checkout-index-basic.sh b/t/t2006-checkout-index-basic.sh
index 7705e3a317..5d119871d4 100755
--- a/t/t2006-checkout-index-basic.sh
+++ b/t/t2006-checkout-index-basic.sh
@@ -3,6 +3,7 @@
 test_description='basic checkout-index tests
 '
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'checkout-index --gobbledegook' '
diff --git a/t/t2023-checkout-m.sh b/t/t2023-checkout-m.sh
index 7b327b7544..81e772fb4e 100755
--- a/t/t2023-checkout-m.sh
+++ b/t/t2023-checkout-m.sh
@@ -7,6 +7,7 @@ Ensures that checkout -m on a resolved file restores the conflicted file'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success setup '
diff --git a/t/t2205-add-worktree-config.sh b/t/t2205-add-worktree-config.sh
index 43d950de64..98265ba1b4 100755
--- a/t/t2205-add-worktree-config.sh
+++ b/t/t2205-add-worktree-config.sh
@@ -17,6 +17,7 @@ outside the repository.  Two instances for which this can occur are tested:
 	   repository can be added to the index.
 	'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success '1a: setup--config worktree' '
diff --git a/t/t3001-ls-files-others-exclude.sh b/t/t3001-ls-files-others-exclude.sh
index e07ac6c6dc..1ed0aa967e 100755
--- a/t/t3001-ls-files-others-exclude.sh
+++ b/t/t3001-ls-files-others-exclude.sh
@@ -103,7 +103,7 @@ test_expect_success 'git ls-files --others with various exclude options.' '
 	test_cmp expect output
 '
 
-test_expect_success !SANITIZE_LEAK 'restore gitignore' '
+test_expect_success 'restore gitignore' '
 	git checkout --ignore-skip-worktree-bits $allignores &&
 	rm .git/index
 '
@@ -126,7 +126,7 @@ cat > expect << EOF
 #	three/
 EOF
 
-test_expect_success !SANITIZE_LEAK 'git status honors core.excludesfile' \
+test_expect_success 'git status honors core.excludesfile' \
 	'test_cmp expect output'
 
 test_expect_success 'trailing slash in exclude allows directory match(1)' '
diff --git a/t/t3012-ls-files-dedup.sh b/t/t3012-ls-files-dedup.sh
index 2682b1f43a..190e2f6eed 100755
--- a/t/t3012-ls-files-dedup.sh
+++ b/t/t3012-ls-files-dedup.sh
@@ -2,6 +2,7 @@
 
 test_description='git ls-files --deduplicate test'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'setup' '
diff --git a/t/t3305-notes-fanout.sh b/t/t3305-notes-fanout.sh
index 64a9915761..22ffe5bcb9 100755
--- a/t/t3305-notes-fanout.sh
+++ b/t/t3305-notes-fanout.sh
@@ -51,7 +51,7 @@ test_expect_success 'creating many notes with git-notes' '
 	done
 '
 
-test_expect_success !SANITIZE_LEAK 'many notes created correctly with git-notes' '
+test_expect_success 'many notes created correctly with git-notes' '
 	git log >output.raw &&
 	grep "^    " output.raw >output &&
 	i=$num_notes &&
diff --git a/t/t4017-diff-retval.sh b/t/t4017-diff-retval.sh
index ed461f481e..5bc28ad9f0 100755
--- a/t/t4017-diff-retval.sh
+++ b/t/t4017-diff-retval.sh
@@ -5,6 +5,7 @@ test_description='Return value of diffs'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'setup' '
diff --git a/t/t4020-diff-external.sh b/t/t4020-diff-external.sh
index 858a5522f9..c1ac09ecc7 100755
--- a/t/t4020-diff-external.sh
+++ b/t/t4020-diff-external.sh
@@ -33,7 +33,7 @@ test_expect_success 'GIT_EXTERNAL_DIFF environment' '
 
 '
 
-test_expect_success !SANITIZE_LEAK 'GIT_EXTERNAL_DIFF environment should apply only to diff' '
+test_expect_success 'GIT_EXTERNAL_DIFF environment should apply only to diff' '
 	GIT_EXTERNAL_DIFF=echo git log -p -1 HEAD >out &&
 	grep "^diff --git a/file b/file" out
 
@@ -74,7 +74,7 @@ test_expect_success 'diff.external' '
 	test_cmp expect actual
 '
 
-test_expect_success !SANITIZE_LEAK 'diff.external should apply only to diff' '
+test_expect_success 'diff.external should apply only to diff' '
 	test_config diff.external echo &&
 	git log -p -1 HEAD >out &&
 	grep "^diff --git a/file b/file" out
diff --git a/t/t4051-diff-function-context.sh b/t/t4051-diff-function-context.sh
index 4838a1df8b..725278ad19 100755
--- a/t/t4051-diff-function-context.sh
+++ b/t/t4051-diff-function-context.sh
@@ -2,6 +2,7 @@
 
 test_description='diff function context'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 dir="$TEST_DIRECTORY/t4051"
diff --git a/t/t4057-diff-combined-paths.sh b/t/t4057-diff-combined-paths.sh
index 04b8a1542a..9a7505cbb8 100755
--- a/t/t4057-diff-combined-paths.sh
+++ b/t/t4057-diff-combined-paths.sh
@@ -5,6 +5,7 @@ test_description='combined diff show only paths that are different to all parent
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # verify that diffc.expect matches output of
diff --git a/t/t4114-apply-typechange.sh b/t/t4114-apply-typechange.sh
index da3e64f811..8ff3640766 100755
--- a/t/t4114-apply-typechange.sh
+++ b/t/t4114-apply-typechange.sh
@@ -7,6 +7,7 @@ test_description='git apply should not get confused with type changes.
 
 '
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'setup repository and commits' '
diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
index f091259a55..a243e3c517 100755
--- a/t/t4301-merge-tree-write-tree.sh
+++ b/t/t4301-merge-tree-write-tree.sh
@@ -2,6 +2,7 @@
 
 test_description='git merge-tree --write-tree'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # This test is ort-specific
diff --git a/t/t5315-pack-objects-compression.sh b/t/t5315-pack-objects-compression.sh
index 8bacd96275..c80ea9e8b7 100755
--- a/t/t5315-pack-objects-compression.sh
+++ b/t/t5315-pack-objects-compression.sh
@@ -2,6 +2,7 @@
 
 test_description='pack-object compression configuration'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success setup '
diff --git a/t/t5351-unpack-large-objects.sh b/t/t5351-unpack-large-objects.sh
index e936f91c3b..8c8af99b84 100755
--- a/t/t5351-unpack-large-objects.sh
+++ b/t/t5351-unpack-large-objects.sh
@@ -5,6 +5,7 @@
 
 test_description='git unpack-objects with large objects'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 prepare_dest () {
diff --git a/t/t5402-post-merge-hook.sh b/t/t5402-post-merge-hook.sh
index 915af2de95..46ebdfbeeb 100755
--- a/t/t5402-post-merge-hook.sh
+++ b/t/t5402-post-merge-hook.sh
@@ -7,6 +7,7 @@ test_description='Test the post-merge hook.'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success setup '
diff --git a/t/t5503-tagfollow.sh b/t/t5503-tagfollow.sh
index 195fc64dd4..5ebbaa4896 100755
--- a/t/t5503-tagfollow.sh
+++ b/t/t5503-tagfollow.sh
@@ -5,6 +5,7 @@ test_description='test automatic tag following'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # End state of the repository:
diff --git a/t/t6102-rev-list-unexpected-objects.sh b/t/t6102-rev-list-unexpected-objects.sh
index cf0195e826..4a9a4436e2 100755
--- a/t/t6102-rev-list-unexpected-objects.sh
+++ b/t/t6102-rev-list-unexpected-objects.sh
@@ -17,7 +17,7 @@ test_expect_success 'setup unexpected non-blob entry' '
 	broken_tree="$(git hash-object -w --literally -t tree broken-tree)"
 '
 
-test_expect_success !SANITIZE_LEAK 'TODO (should fail!): traverse unexpected non-blob entry (lone)' '
+test_expect_success 'TODO (should fail!): traverse unexpected non-blob entry (lone)' '
 	sed "s/Z$//" >expect <<-EOF &&
 	$broken_tree Z
 	$tree foo
@@ -121,7 +121,7 @@ test_expect_success 'setup unexpected non-blob tag' '
 	tag=$(git hash-object -w --literally -t tag broken-tag)
 '
 
-test_expect_success !SANITIZE_LEAK 'TODO (should fail!): traverse unexpected non-blob tag (lone)' '
+test_expect_success 'TODO (should fail!): traverse unexpected non-blob tag (lone)' '
 	git rev-list --objects $tag
 '
 
diff --git a/t/t6404-recursive-merge.sh b/t/t6404-recursive-merge.sh
index b8735c6db4..36215518b6 100755
--- a/t/t6404-recursive-merge.sh
+++ b/t/t6404-recursive-merge.sh
@@ -4,6 +4,7 @@ test_description='Test merge without common ancestors'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # This scenario is based on a real-world repository of Shawn Pearce.
diff --git a/t/t6405-merge-symlinks.sh b/t/t6405-merge-symlinks.sh
index 7435fce71e..29e2b25ce5 100755
--- a/t/t6405-merge-symlinks.sh
+++ b/t/t6405-merge-symlinks.sh
@@ -11,6 +11,7 @@ if core.symlinks is false.'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'setup' '
diff --git a/t/t6407-merge-binary.sh b/t/t6407-merge-binary.sh
index 0753fc95f4..e8a28717ce 100755
--- a/t/t6407-merge-binary.sh
+++ b/t/t6407-merge-binary.sh
@@ -5,7 +5,6 @@ test_description='ask merge-recursive to merge binary files'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
-TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success setup '
diff --git a/t/t6408-merge-up-to-date.sh b/t/t6408-merge-up-to-date.sh
index 7763c1ba98..8a1ba6d23a 100755
--- a/t/t6408-merge-up-to-date.sh
+++ b/t/t6408-merge-up-to-date.sh
@@ -2,6 +2,7 @@
 
 test_description='merge fast-forward and up to date'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success setup '
diff --git a/t/t6411-merge-filemode.sh b/t/t6411-merge-filemode.sh
index 6ae2489286..b6182723aa 100755
--- a/t/t6411-merge-filemode.sh
+++ b/t/t6411-merge-filemode.sh
@@ -4,6 +4,7 @@ test_description='merge: handle file mode'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'set up mode change in one branch' '
diff --git a/t/t6413-merge-crlf.sh b/t/t6413-merge-crlf.sh
index affea255fe..b4f4a313f4 100755
--- a/t/t6413-merge-crlf.sh
+++ b/t/t6413-merge-crlf.sh
@@ -11,6 +11,7 @@ test_description='merge conflict in crlf repo
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success setup '
diff --git a/t/t6425-merge-rename-delete.sh b/t/t6425-merge-rename-delete.sh
index 459b431a60..93cd2869b1 100755
--- a/t/t6425-merge-rename-delete.sh
+++ b/t/t6425-merge-rename-delete.sh
@@ -4,6 +4,7 @@ test_description='Merge-recursive rename/delete conflict message'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'rename/delete' '
diff --git a/t/t6431-merge-criscross.sh b/t/t6431-merge-criscross.sh
index 3824756a02..3fe14cd73e 100755
--- a/t/t6431-merge-criscross.sh
+++ b/t/t6431-merge-criscross.sh
@@ -2,6 +2,7 @@
 
 test_description='merge-recursive backend test'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 #         A      <- create some files
diff --git a/t/t7060-wtstatus.sh b/t/t7060-wtstatus.sh
index 0f4344c55e..aaeb4a5334 100755
--- a/t/t7060-wtstatus.sh
+++ b/t/t7060-wtstatus.sh
@@ -5,6 +5,7 @@ test_description='basic work tree status reporting'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success setup '
diff --git a/t/t7062-wtstatus-ignorecase.sh b/t/t7062-wtstatus-ignorecase.sh
index 73709dbeee..caf372a3d4 100755
--- a/t/t7062-wtstatus-ignorecase.sh
+++ b/t/t7062-wtstatus-ignorecase.sh
@@ -2,6 +2,7 @@
 
 test_description='git-status with core.ignorecase=true'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'status with hash collisions' '
diff --git a/t/t7110-reset-merge.sh b/t/t7110-reset-merge.sh
index 3d62e10b53..eb881be95b 100755
--- a/t/t7110-reset-merge.sh
+++ b/t/t7110-reset-merge.sh
@@ -5,6 +5,7 @@
 
 test_description='Tests for "git reset" with "--merge" and "--keep" options'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success setup '
diff --git a/t/t7111-reset-table.sh b/t/t7111-reset-table.sh
index ce421ad5ac..78f25c1c7e 100755
--- a/t/t7111-reset-table.sh
+++ b/t/t7111-reset-table.sh
@@ -5,6 +5,7 @@
 
 test_description='Tests to check that "reset" options follow a known table'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 
diff --git a/t/t7609-mergetool--lib.sh b/t/t7609-mergetool--lib.sh
index 330d6d603d..8b1c3bd39f 100755
--- a/t/t7609-mergetool--lib.sh
+++ b/t/t7609-mergetool--lib.sh
@@ -4,6 +4,7 @@ test_description='git mergetool
 
 Testing basic merge tools options'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'mergetool --tool=vimdiff creates the expected layout' '
diff --git a/t/t9100-git-svn-basic.sh b/t/t9100-git-svn-basic.sh
index 7c5b847f58..fea41b3c36 100755
--- a/t/t9100-git-svn-basic.sh
+++ b/t/t9100-git-svn-basic.sh
@@ -8,7 +8,6 @@ test_description='git svn basic tests'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
-TEST_FAILS_SANITIZE_LEAK=true
 . ./lib-git-svn.sh
 
 prepare_utf8_locale
diff --git a/t/t9700-perl-git.sh b/t/t9700-perl-git.sh
index 102c133112..4aa5d90d32 100755
--- a/t/t9700-perl-git.sh
+++ b/t/t9700-perl-git.sh
@@ -4,17 +4,12 @@
 #
 
 test_description='perl interface (Git.pm)'
+
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-perl.sh
 
-if ! test_have_prereq PERL; then
-	skip_all='skipping perl interface tests, perl not available'
-	test_done
-fi
-
-perl -MTest::More -e 0 2>/dev/null || {
-	skip_all="Perl Test::More unavailable, skipping test"
-	test_done
-}
+skip_all_if_no_Test_More
 
 # set up test repository
 
@@ -50,11 +45,9 @@ test_expect_success \
      git config --add test.pathmulti bar
      '
 
-# The external test will outputs its own plan
-test_external_has_tap=1
-
-test_external_without_stderr \
-    'Perl API' \
-    perl "$TEST_DIRECTORY"/t9700/test.pl
+test_expect_success 'use t9700/test.pl to test Git.pm' '
+	"$PERL_PATH" "$TEST_DIRECTORY"/t9700/test.pl 2>stderr &&
+	test_must_be_empty stderr
+'
 
 test_done
diff --git a/t/t9901-git-web--browse.sh b/t/t9901-git-web--browse.sh
index de7152f827..19f56e5680 100755
--- a/t/t9901-git-web--browse.sh
+++ b/t/t9901-git-web--browse.sh
@@ -5,6 +5,7 @@ test_description='git web--browse basic tests
 
 This test checks that git web--browse can handle various valid URLs.'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_web_browse () {
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 8c44856eae..c6479f24eb 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -633,7 +633,7 @@ test_hook () {
 # - Explicitly using test_have_prereq.
 #
 # - Implicitly by specifying the prerequisite tag in the calls to
-#   test_expect_{success,failure} and test_external{,_without_stderr}.
+#   test_expect_{success,failure}
 #
 # The single parameter is the prerequisite tag (a simple word, in all
 # capital letters by convention).
@@ -835,93 +835,6 @@ test_expect_success () {
 	test_finish_
 }
 
-# test_external runs external test scripts that provide continuous
-# test output about their progress, and succeeds/fails on
-# zero/non-zero exit code.  It outputs the test output on stdout even
-# in non-verbose mode, and announces the external script with "# run
-# <n>: ..." before running it.  When providing relative paths, keep in
-# mind that all scripts run in "trash directory".
-# Usage: test_external description command arguments...
-# Example: test_external 'Perl API' perl ../path/to/test.pl
-test_external () {
-	test "$#" = 4 && { test_prereq=$1; shift; } || test_prereq=
-	test "$#" = 3 ||
-	BUG "not 3 or 4 parameters to test_external"
-	descr="$1"
-	shift
-	test_verify_prereq
-	export test_prereq
-	if ! test_skip "$descr" "$@"
-	then
-		# Announce the script to reduce confusion about the
-		# test output that follows.
-		say_color "" "# run $test_count: $descr ($*)"
-		# Export TEST_DIRECTORY, TRASH_DIRECTORY and GIT_TEST_LONG
-		# to be able to use them in script
-		export TEST_DIRECTORY TRASH_DIRECTORY GIT_TEST_LONG
-		# Run command; redirect its stderr to &4 as in
-		# test_run_, but keep its stdout on our stdout even in
-		# non-verbose mode.
-		"$@" 2>&4
-		if test "$?" = 0
-		then
-			if test $test_external_has_tap -eq 0; then
-				test_ok_ "$descr"
-			else
-				say_color "" "# test_external test $descr was ok"
-				test_success=$(($test_success + 1))
-			fi
-		else
-			if test $test_external_has_tap -eq 0; then
-				test_failure_ "$descr" "$@"
-			else
-				say_color error "# test_external test $descr failed: $@"
-				test_failure=$(($test_failure + 1))
-			fi
-		fi
-	fi
-}
-
-# Like test_external, but in addition tests that the command generated
-# no output on stderr.
-test_external_without_stderr () {
-	# The temporary file has no (and must have no) security
-	# implications.
-	tmp=${TMPDIR:-/tmp}
-	stderr="$tmp/git-external-stderr.$$.tmp"
-	test_external "$@" 4> "$stderr"
-	test -f "$stderr" || error "Internal error: $stderr disappeared."
-	descr="no stderr: $1"
-	shift
-	say >&3 "# expecting no stderr from previous command"
-	if test ! -s "$stderr"
-	then
-		rm "$stderr"
-
-		if test $test_external_has_tap -eq 0; then
-			test_ok_ "$descr"
-		else
-			say_color "" "# test_external_without_stderr test $descr was ok"
-			test_success=$(($test_success + 1))
-		fi
-	else
-		if test "$verbose" = t
-		then
-			output=$(echo; echo "# Stderr is:"; cat "$stderr")
-		else
-			output=
-		fi
-		# rm first in case test_failure exits.
-		rm "$stderr"
-		if test $test_external_has_tap -eq 0; then
-			test_failure_ "$descr" "$@" "$output"
-		else
-			say_color error "# test_external_without_stderr test $descr failed: $@: $output"
-			test_failure=$(($test_failure + 1))
-		fi
-	fi
-}
-
 # debugging-friendly alternatives to "test [-f|-d|-e]"
 # The commands test the existence or non-existence of $1
 test_path_is_file () {
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 7726d1da88..10258def7b 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -238,6 +238,9 @@ parse_option () {
 			;;
 		esac
 		;;
+	--invert-exit-code)
+		invert_exit_code=t
+		;;
 	*)
 		echo "error: unknown test option '$opt'" >&2; exit 1 ;;
 	esac
@@ -302,6 +305,11 @@ TEST_NUMBER="${TEST_NAME%%-*}"
 TEST_NUMBER="${TEST_NUMBER#t}"
 TEST_RESULTS_DIR="$TEST_OUTPUT_DIRECTORY/test-results"
 TEST_RESULTS_BASE="$TEST_RESULTS_DIR/$TEST_NAME$TEST_STRESS_JOB_SFX"
+TEST_RESULTS_SAN_FILE_PFX=trace
+TEST_RESULTS_SAN_DIR_SFX=leak
+TEST_RESULTS_SAN_FILE=
+TEST_RESULTS_SAN_DIR="$TEST_RESULTS_DIR/$TEST_NAME.$TEST_RESULTS_SAN_DIR_SFX"
+TEST_RESULTS_SAN_DIR_NR_LEAKS_STARTUP=
 TRASH_DIRECTORY="trash directory.$TEST_NAME$TEST_STRESS_JOB_SFX"
 test -n "$root" && TRASH_DIRECTORY="$root/$TRASH_DIRECTORY"
 case "$TRASH_DIRECTORY" in
@@ -309,6 +317,16 @@ case "$TRASH_DIRECTORY" in
  *) TRASH_DIRECTORY="$TEST_OUTPUT_DIRECTORY/$TRASH_DIRECTORY" ;;
 esac
 
+# Utility functions using $TEST_RESULTS_* variables
+nr_san_dir_leaks_ () {
+	# stderr piped to /dev/null because the directory may have
+	# been "rmdir"'d already.
+	find "$TEST_RESULTS_SAN_DIR" \
+		-type f \
+		-name "$TEST_RESULTS_SAN_FILE_PFX.*" 2>/dev/null |
+	wc -l
+}
+
 # If --stress was passed, run this test repeatedly in several parallel loops.
 if test "$GIT_TEST_STRESS_STARTED" = "done"
 then
@@ -788,15 +806,31 @@ test_ok_ () {
 	finalize_test_case_output ok "$@"
 }
 
+_invert_exit_code_failure_end_blurb () {
+	say_color warn "# faked up failures as TODO & now exiting with 0 due to --invert-exit-code"
+}
+
 test_failure_ () {
 	failure_label=$1
 	test_failure=$(($test_failure + 1))
-	say_color error "not ok $test_count - $1"
+	local pfx=""
+	if test -n "$invert_exit_code" # && test -n "$HARNESS_ACTIVE"
+	then
+		pfx="# TODO induced breakage (--invert-exit-code):"
+	fi
+	say_color error "not ok $test_count - ${pfx:+$pfx }$1"
 	shift
 	printf '%s\n' "$*" | sed -e 's/^/#	/'
 	if test -n "$immediate"
 	then
 		say_color error "1..$test_count"
+		if test -n "$invert_exit_code"
+		then
+			finalize_test_output
+			_invert_exit_code_failure_end_blurb
+			GIT_EXIT_OK=t
+			exit 0
+		fi
 		_error_exit
 	fi
 	finalize_test_case_output failure "$failure_label" "$@"
@@ -804,14 +838,14 @@ test_failure_ () {
 
 test_known_broken_ok_ () {
 	test_fixed=$(($test_fixed+1))
-	say_color error "ok $test_count - $@ # TODO known breakage vanished"
-	finalize_test_case_output fixed "$@"
+	say_color error "ok $test_count - $1 # TODO known breakage vanished"
+	finalize_test_case_output fixed "$1"
 }
 
 test_known_broken_failure_ () {
 	test_broken=$(($test_broken+1))
-	say_color warn "not ok $test_count - $@ # TODO known breakage"
-	finalize_test_case_output broken "$@"
+	say_color warn "not ok $test_count - $1 # TODO known breakage"
+	finalize_test_case_output broken "$1"
 }
 
 test_debug () {
@@ -1168,9 +1202,67 @@ test_atexit_handler () {
 	teardown_malloc_check
 }
 
-test_done () {
-	GIT_EXIT_OK=t
+sanitize_leak_log_message_ () {
+	local new="$1" &&
+	local old="$2" &&
+	local file="$3" &&
 
+	printf "With SANITIZE=leak at exit we have %d leak logs, but started with %d
+
+This means that we have a blindspot where git is leaking but we're
+losing the exit code somewhere, or not propagating it appropriately
+upwards!
+
+See the logs at \"%s.*\";
+those logs are reproduced below." \
+	       "$new" "$old" "$file"
+}
+
+check_test_results_san_file_ () {
+	if test -z "$TEST_RESULTS_SAN_FILE"
+	then
+		return
+	fi &&
+	local old="$TEST_RESULTS_SAN_DIR_NR_LEAKS_STARTUP" &&
+	local new="$(nr_san_dir_leaks_)" &&
+
+	if test $new -le $old
+	then
+		return
+	fi &&
+	local out="$(sanitize_leak_log_message_ "$new" "$old" "$TEST_RESULTS_SAN_FILE")" &&
+	say_color error "$out" &&
+	if test "$old" != 0
+	then
+		echo &&
+		say_color error "The logs include output from past runs to avoid" &&
+		say_color error "that remove 'test-results' between runs."
+	fi &&
+	say_color error "$(cat "$TEST_RESULTS_SAN_FILE".*)" &&
+
+	if test -n "$passes_sanitize_leak" && test "$test_failure" = 0
+	then
+		say "As TEST_PASSES_SANITIZE_LEAK=true and our logs show we're leaking, exit non-zero!" &&
+		invert_exit_code=t
+	elif test -n "$passes_sanitize_leak"
+	then
+		say "As TEST_PASSES_SANITIZE_LEAK=true and our logs show we're leaking, and we're failing for other reasons too..." &&
+		invert_exit_code=
+	elif test -n "$sanitize_leak_check" && test "$test_failure" = 0
+	then
+		say "As TEST_PASSES_SANITIZE_LEAK=true isn't set the above leak is 'ok' with GIT_TEST_PASSING_SANITIZE_LEAK=check" &&
+		invert_exit_code=
+	elif test -n "$sanitize_leak_check"
+	then
+		say "As TEST_PASSES_SANITIZE_LEAK=true isn't set the above leak is 'ok' with GIT_TEST_PASSING_SANITIZE_LEAK=check" &&
+		invert_exit_code=t
+	else
+		say "With GIT_TEST_SANITIZE_LEAK_LOG=true our logs revealed a memory leak, exit non-zero!" &&
+		invert_exit_code=t
+	fi
+}
+
+test_done () {
 	# Run the atexit commands _before_ the trash directory is
 	# removed, so the commands can access pidfiles and socket files.
 	test_atexit_handler
@@ -1210,28 +1302,32 @@ test_done () {
 	fi
 	case "$test_failure" in
 	0)
-		if test $test_external_has_tap -eq 0
+		if test $test_remaining -gt 0
 		then
-			if test $test_remaining -gt 0
-			then
-				say_color pass "# passed all $msg"
-			fi
-
-			# Maybe print SKIP message
-			test -z "$skip_all" || skip_all="# SKIP $skip_all"
-			case "$test_count" in
-			0)
-				say "1..$test_count${skip_all:+ $skip_all}"
-				;;
-			*)
-				test -z "$skip_all" ||
-				say_color warn "$skip_all"
-				say "1..$test_count"
-				;;
-			esac
+			say_color pass "# passed all $msg"
 		fi
 
-		if test -z "$debug" && test -n "$remove_trash"
+		# Maybe print SKIP message
+		test -z "$skip_all" || skip_all="# SKIP $skip_all"
+		case "$test_count" in
+		0)
+			say "1..$test_count${skip_all:+ $skip_all}"
+			;;
+		*)
+			test -z "$skip_all" ||
+			say_color warn "$skip_all"
+			say "1..$test_count"
+			;;
+		esac
+
+		if test -n "$stress" && test -n "$invert_exit_code"
+		then
+			# We're about to move our "$TRASH_DIRECTORY"
+			# to "$TRASH_DIRECTORY.stress-failed" if
+			# --stress is combined with
+			# --invert-exit-code.
+			say "with --stress and --invert-exit-code we're not removing '$TRASH_DIRECTORY'"
+		elif test -z "$debug" && test -n "$remove_trash"
 		then
 			test -d "$TRASH_DIRECTORY" ||
 			error "Tests passed but trash directory already removed before test cleanup; aborting"
@@ -1244,17 +1340,35 @@ test_done () {
 			} ||
 			error "Tests passed but test cleanup failed; aborting"
 		fi
+
+		check_test_results_san_file_ "$test_failure"
+
+		if test -z "$skip_all" && test -n "$invert_exit_code"
+		then
+			say_color warn "# faking up non-zero exit with --invert-exit-code"
+			GIT_EXIT_OK=t
+			exit 1
+		fi
+
 		test_at_end_hook_
 
+		GIT_EXIT_OK=t
 		exit 0 ;;
 
 	*)
-		if test $test_external_has_tap -eq 0
+		say_color error "# failed $test_failure among $msg"
+		say "1..$test_count"
+
+		check_test_results_san_file_ "$test_failure"
+
+		if test -n "$invert_exit_code"
 		then
-			say_color error "# failed $test_failure among $msg"
-			say "1..$test_count"
+			_invert_exit_code_failure_end_blurb
+			GIT_EXIT_OK=t
+			exit 0
 		fi
 
+		GIT_EXIT_OK=t
 		exit 1 ;;
 
 	esac
@@ -1387,14 +1501,12 @@ fi
 GITPERLLIB="$GIT_BUILD_DIR"/perl/build/lib
 export GITPERLLIB
 test -d "$GIT_BUILD_DIR"/templates/blt || {
-	error "You haven't built things yet, have you?"
+	BAIL_OUT "You haven't built things yet, have you?"
 }
 
 if ! test -x "$GIT_BUILD_DIR"/t/helper/test-tool$X
 then
-	echo >&2 'You need to build test-tool:'
-	echo >&2 'Run "make t/helper/test-tool" in the source (toplevel) directory'
-	exit 1
+	BAIL_OUT 'You need to build test-tool; Run "make t/helper/test-tool" in the source (toplevel) directory'
 fi
 
 # Are we running this test at all?
@@ -1408,24 +1520,70 @@ then
 	test_done
 fi
 
-# skip non-whitelisted tests when compiled with SANITIZE=leak
+BAIL_OUT_ENV_NEEDS_SANITIZE_LEAK () {
+	BAIL_OUT "$1 has no effect except when compiled with SANITIZE=leak"
+}
+
 if test -n "$SANITIZE_LEAK"
 then
-	if test_bool_env GIT_TEST_PASSING_SANITIZE_LEAK false
-	then
-		# We need to see it in "git env--helper" (via
-		# test_bool_env)
-		export TEST_PASSES_SANITIZE_LEAK
+	# Normalize with test_bool_env
+	passes_sanitize_leak=
 
-		if ! test_bool_env TEST_PASSES_SANITIZE_LEAK false
-		then
-			skip_all="skipping $this_test under GIT_TEST_PASSING_SANITIZE_LEAK=true"
-			test_done
-		fi
+	# We need to see TEST_PASSES_SANITIZE_LEAK in "git
+	# env--helper" (via test_bool_env)
+	export TEST_PASSES_SANITIZE_LEAK
+	if test_bool_env TEST_PASSES_SANITIZE_LEAK false
+	then
+		passes_sanitize_leak=t
 	fi
-elif test_bool_env GIT_TEST_PASSING_SANITIZE_LEAK false
+
+	if test "$GIT_TEST_PASSING_SANITIZE_LEAK" = "check"
+	then
+		sanitize_leak_check=t
+		if test -n "$invert_exit_code"
+		then
+			BAIL_OUT "cannot use --invert-exit-code under GIT_TEST_PASSING_SANITIZE_LEAK=check"
+		fi
+
+		if test -z "$passes_sanitize_leak"
+		then
+			say "in GIT_TEST_PASSING_SANITIZE_LEAK=check mode, setting --invert-exit-code for TEST_PASSES_SANITIZE_LEAK != true"
+			invert_exit_code=t
+		fi
+	elif test -z "$passes_sanitize_leak" &&
+	     test_bool_env GIT_TEST_PASSING_SANITIZE_LEAK false
+	then
+		skip_all="skipping $this_test under GIT_TEST_PASSING_SANITIZE_LEAK=true"
+		test_done
+	fi
+
+	if test_bool_env GIT_TEST_SANITIZE_LEAK_LOG false
+	then
+		if ! mkdir -p "$TEST_RESULTS_SAN_DIR"
+		then
+			BAIL_OUT "cannot create $TEST_RESULTS_SAN_DIR"
+		fi &&
+		TEST_RESULTS_SAN_FILE="$TEST_RESULTS_SAN_DIR/$TEST_RESULTS_SAN_FILE_PFX"
+
+		# In case "test-results" is left over from a previous
+		# run: Only report if new leaks show up.
+		TEST_RESULTS_SAN_DIR_NR_LEAKS_STARTUP=$(nr_san_dir_leaks_)
+
+		# Don't litter *.leak dirs if there was nothing to report
+		test_atexit "rmdir \"$TEST_RESULTS_SAN_DIR\" 2>/dev/null || :"
+
+		prepend_var LSAN_OPTIONS : dedup_token_length=9999
+		prepend_var LSAN_OPTIONS : log_exe_name=1
+		prepend_var LSAN_OPTIONS : log_path=\"$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 "GIT_TEST_PASSING_SANITIZE_LEAK=true has no effect except when compiled with SANITIZE=leak"
+	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
 
 # Last-minute variable setup
@@ -1448,9 +1606,7 @@ remove_trash_directory () {
 
 # Test repository
 remove_trash_directory "$TRASH_DIRECTORY" || {
-	GIT_EXIT_OK=t
-	echo >&5 "FATAL: Cannot prepare test area"
-	exit 1
+	BAIL_OUT 'cannot prepare test area'
 }
 
 remove_trash=t
@@ -1466,7 +1622,7 @@ fi
 
 # Use -P to resolve symlinks in our working directory so that the cwd
 # in subprocesses like git equals our $PWD (for pathname comparisons).
-cd -P "$TRASH_DIRECTORY" || exit 1
+cd -P "$TRASH_DIRECTORY" || BAIL_OUT "cannot cd -P to \"$TRASH_DIRECTORY\""
 
 start_test_output "$0"
 
diff --git a/upload-pack.c b/upload-pack.c
index 09f48317b0..b217a1f469 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -455,6 +455,7 @@ static void create_pack_file(struct upload_pack_data *pack_data,
 	return;
 
  fail:
+	free(output_state);
 	send_client_data(3, abort_msg, sizeof(abort_msg),
 			 pack_data->use_sideband);
 	die("git upload-pack: %s", abort_msg);