From 4dd91f95f79b38ae218dfc95921ae0d243394713 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michael=20Mur=C3=A9?= <michael.mure@consensys.net>
Date: Mon, 2 Sep 2024 18:08:49 +0200
Subject: [PATCH] selector: workaround panic() go-ipld-prime with negative
 index

Waiting on https://github.com/ipld/go-ipld-prime/pull/571 to be released.
---
 capability/policy/selector/selector.go | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/capability/policy/selector/selector.go b/capability/policy/selector/selector.go
index 49f2f8e..1dba97e 100644
--- a/capability/policy/selector/selector.go
+++ b/capability/policy/selector/selector.go
@@ -183,6 +183,12 @@ func resolve(sel Selector, subject ipld.Node, at []string) (ipld.Node, []ipld.No
 				if idx < 0 {
 					idx = cur.Length() + idx
 				}
+				if idx < 0 {
+					// necessary until https://github.com/ipld/go-ipld-prime/pull/571
+					// after, isMissing() below will work
+					// TODO: remove
+					return nil, nil, newResolutionError(fmt.Sprintf("index out of bounds: %d", seg.Index()), at)
+				}
 				n, err := cur.LookupByIndex(idx)
 				if err != nil {
 					if isMissing(err) {