Address @chelseakomlo comments

command/agent/config.go

@@ -940,7 +940,7 @@ func isTooManyColons(err error) bool {
 	return err != nil && strings.Contains(err.Error(), tooManyColons)
 }
 
-// Merge is used to merge two ACL configs together
+// Merge is used to merge two ACL configs together. The settings from the input always take precedence.
 func (a *ACLConfig) Merge(b *ACLConfig) *ACLConfig {
 	result := *a
 

nomad/acl_endpoint.go

@@ -108,6 +108,9 @@ func (a *ACL) ListPolicies(args *structs.ACLPolicyListRequest, reply *structs.AC
 			if err != nil {
 				return err
 			}
+
+			// Ensure we never set the index to zero, otherwise a blocking query cannot be used.
+			// We floor the index at one, since realistically the first write must have a higher index.
 			if index == 0 {
 				index = 1
 			}