From 7ad940844c0c82447aa40777451da9fb72a2c3fb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michael=20Mur=C3=A9?= <batolettre@gmail.com>
Date: Wed, 23 Oct 2024 11:31:41 +0200
Subject: [PATCH] selector: disallow backward slicing

---
 pkg/policy/selector/selector.go | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/pkg/policy/selector/selector.go b/pkg/policy/selector/selector.go
index 09d6dc4..859e2bf 100644
--- a/pkg/policy/selector/selector.go
+++ b/pkg/policy/selector/selector.go
@@ -344,9 +344,10 @@ func resolveSliceIndices(slice []int64, length int64) (start int64, end int64) {
 		end = length + slice[1]
 	}
 
-	// TODO: is backward iteration allowed?
-	// if yes, we need to return a +1 or -1 "step"
-	// if no, we need to error
+	if start >= end {
+		// backward iteration is not allowed, shortcut to an empty result
+		start, end = 0, 0
+	}
 
 	return start, end
 }