t: prepare conditional test execution for set -e

We have some test in our test suite where we use the pattern of
`test ... && test_expect_succeess` to conditionally execute a test. The
problem is that when we decide to not execute the test, we'll indeed
skip the test, but the overall statement will also be unsuccessful. This
will become a problem once we enable `set -e`.

Prepare for this future by turning this into a proper conditional, which
is also a bit easier to read overall.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

t/t4032-diff-inter-hunk-context.sh

@@ -40,11 +40,13 @@ t() {
 		test $(git $cmd $file | grep '^@@ ' | wc -l) = $hunks
 	"
 
-	test -f $expected &&
-	test_expect_success "$label: check output" "
-		git $cmd $file | grep -v '^index ' >actual &&
-		test_cmp $expected actual
-	"
+	if test -f $expected
+	then
+		test_expect_success "$label: check output" "
+			git $cmd $file | grep -v '^index ' >actual &&
+			test_cmp $expected actual
+		"
+	fi
 }
 
 cat <<EOF >expected.f1.0.1 || exit 1

t/t7450-bad-git-dotfiles.sh

@@ -220,17 +220,19 @@ check_dotx_symlink () {
 		)
 	'
 
-	test -n "$refuse_index" &&
-	test_expect_success "refuse to load symlinked $name into index ($type)" '
-		test_must_fail \
-			git -C $dir \
-			    -c core.protectntfs \
-			    -c core.protecthfs \
-			    read-tree $tree 2>err &&
-		grep "invalid path.*$name" err &&
-		git -C $dir ls-files -s >out &&
-		test_must_be_empty out
-	'
+	if test -n "$refuse_index"
+	then
+		test_expect_success "refuse to load symlinked $name into index ($type)" '
+			test_must_fail \
+				git -C $dir \
+				    -c core.protectntfs \
+				    -c core.protecthfs \
+				    read-tree $tree 2>err &&
+			grep "invalid path.*$name" err &&
+			git -C $dir ls-files -s >out &&
+			test_must_be_empty out
+		'
+	fi
 }
 
 check_dotx_symlink gitmodules vanilla .gitmodules