chainlint.pl: don't flag broken &&-chain if failure indicated explicitly

There are quite a few tests which print an error messages and then
explicitly signal failure with `false`, `return 1`, or `exit 1` as the
final command in an `if` branch. In these cases, the tests don't bother
maintaining the &&-chain between `echo` and the explicit "test failed"
indicator. Since such constructs are manually signaling failure, their
&&-chain breakage is legitimate and safe -- both for the command
immediately preceding `false`, `return`, or `exit`, as well as for all
preceding commands in the `if` branch. Therefore, stop flagging &&-chain
breakage in these sorts of cases.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/t/chainlint/chain-break-return-exit.test b/t/chainlint/chain-break-return-exit.test
index e2b059933a..46542edf88 100644
--- a/t/chainlint/chain-break-return-exit.test
+++ b/t/chainlint/chain-break-return-exit.test
@@ -1,3 +1,21 @@
+case "$(git ls-files)" in
+one) echo pass one ;;
+# LINT: broken &&-chain okay if explicit "return 1" signals failuire
+*) echo bad one; return 1 ;;
+esac &&
+(
+	case "$(git ls-files)" in
+	two) echo pass two ;;
+# LINT: broken &&-chain okay if explicit "exit 1" signals failuire
+	*) echo bad two; exit 1 ;;
+	esac
+) &&
+case "$(git ls-files)" in
+dir/two"$LF"one) echo pass both ;;
+# LINT: broken &&-chain okay if explicit "return 1" signals failuire
+*) echo bad; return 1 ;;
+esac &&
+
 for i in 1 2 3 4 ; do
 # LINT: broken &&-chain okay if explicit "return $?" signals failure
 	git checkout main -b $i || return $?