Merge branch 'jk/test-chain-lint'

Developer support to automatically detect broken &&-chain in the
test scripts is now turned on by default.

* jk/test-chain-lint:
  test-lib: turn on GIT_TEST_CHAIN_LINT by default
  t7502-commit.sh: fix a broken and-chain

t/t7502-commit.sh

@@ -370,7 +370,7 @@ exit 0
 EOF
 
 test_expect_success !AUTOIDENT 'do not fire editor when committer is bogus' '
-	>.git/result
+	>.git/result &&
 	>expect &&
 
 	echo >>negative &&

t/test-lib.sh

@@ -529,7 +529,7 @@ test_run_ () {
 	test_cleanup=:
 	expecting_failure=$2
 
-	if test "${GIT_TEST_CHAIN_LINT:-0}" != 0; then
+	if test "${GIT_TEST_CHAIN_LINT:-1}" != 0; then
 		# 117 is magic because it is unlikely to match the exit
 		# code of other programs
 		test_eval_ "(exit 117) && $1"