t: wrap complicated expect_code users in a block

If we are expecting a command to produce a particular exit
code, we can use test_expect_code. However, some cases are
more complicated, and want to accept one of a range of exit
codes. For these, we end up with something like:

  cmd;
  case "$?" in
  ...

That unfortunately breaks the &&-chain and fools
--chain-lint. Since these special cases are so few, we can
wrap them in a block, like this:

  { cmd; ret=$?; } &&
  case "$ret" in
  ...

This accomplishes the same thing, and retains the &&-chain
(the exit status fed to the && is that of the assignment,
which should always be true). It's technically longer, but
it is probably a good thing for unusual code like this to
stand out.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t0005-signals.sh

@@ -10,8 +10,8 @@ one
 EOF
 
 test_expect_success 'sigchain works' '
-	test-sigchain >actual
-	case "$?" in
+	{ test-sigchain >actual; ret=$?; } &&
+	case "$ret" in
 	143) true ;; # POSIX w/ SIGTERM=15
 	271) true ;; # ksh w/ SIGTERM=15
 	  3) true ;; # Windows

t/t4026-color.sh

@@ -111,9 +111,9 @@ test_expect_success 'unknown color slots are ignored (branch)' '
 '
 
 test_expect_success 'unknown color slots are ignored (status)' '
-	git config color.status.nosuchslotwilleverbedefined white || exit
-	git status
-	case $? in 0|1) : ok ;; *) false ;; esac
+	git config color.status.nosuchslotwilleverbedefined white &&
+	{ git status; ret=$?; } &&
+	case $ret in 0|1) : ok ;; *) false ;; esac
 '
 
 test_done

t/t5004-archive-corner-cases.sh

@@ -66,8 +66,10 @@ test_expect_success UNZIP 'zip archive of empty tree is empty' '
 	# handle the empty repo at all, making our later check of its exit code
 	# a no-op). But we cannot do anything reasonable except skip the test
 	# on such platforms anyway, and this is the moral equivalent.
-	"$GIT_UNZIP" "$TEST_DIRECTORY"/t5004/empty.zip
-	expect_code=$?
+	{
+		"$GIT_UNZIP" "$TEST_DIRECTORY"/t5004/empty.zip
+		expect_code=$?
+	} &&
 
 	git archive --format=zip HEAD >empty.zip &&
 	make_dir extract &&

t/t5512-ls-remote.sh

@@ -103,8 +103,10 @@ test_expect_success 'confuses pattern as remote when no remote specified' '
 '
 
 test_expect_success 'die with non-2 for wrong repository even with --exit-code' '
-	git ls-remote --exit-code ./no-such-repository ;# not &&
-	status=$? &&
+	{
+		git ls-remote --exit-code ./no-such-repository
+		status=$?
+	} &&
 	test $status != 2 && test $status != 0
 '