fix(rpn): use < instead of <= for _sentinel in parseCategory

parseCategory iterated over _sentinel itself, causing it to return
true for the sentinel value (an invalid category). Use strict less-
than so only valid categories match.

1 files changed, 1 insertions, 1 deletions

diff --git a/internal/rpn/operations_metric_cmd.go b/internal/rpn/operations_metric_cmd.go
index 61e3f82..8e0e519 100644
--- a/internal/rpn/operations_metric_cmd.go
+++ b/internal/rpn/operations_metric_cmd.go
@@ -85,7 +85,7 @@ func (o *Operations) MetricCompatible(stack *Stack) (string, error) {
 // so adding a new Category constant (between Universal and _sentinel) automatically
 // makes it available here without modifying this function.
 func parseCategory(name string) (Category, bool) {
-	for cat := Category(0); cat <= _sentinel; cat++ {
+	for cat := Category(0); cat < _sentinel; cat++ {
 		if cat.String() == name {
 			return cat, true
 		}