internal/rosa: fix GNU testsuite edge case

For segments with a single test.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/builtins.go

@@ -107,7 +107,7 @@ func skipGNUTests(tests ...int64) string {
 			buf.WriteString(strconv.Itoa(int(n - 1)))
 			buf.WriteString(" ")
 		}
-		if i == len(tests)-1 || tests[i+1] != n+1 {
+		if i == len(tests)-1 || (tests[i+1] != n+1 && tests[i+1] != n+2) {
 			buf.WriteString(strconv.Itoa(int(n + 1)))
 			buf.WriteString("-")
 		}

internal/rosa/builtins_test.go

@@ -16,6 +16,7 @@ func TestSkipGNUTests(t *testing.T) {
 	}{
 		{[]int64{764}, "1-763 765-"},
 		{[]int64{764, 0xcafe, 37, 9}, "1-8 10-36 38-763 765-51965 51967-"},
+		{[]int64{168, 170, 623, 764}, "1-167 169 171-622 624-763 765-"},
 		{[]int64{1, 2, 0xbed}, "3-3052 3054-"},
 		{[]int64{3, 4}, "1-2 5-"},
 	}