From 85a10e511396e63e4ab0f7110517b87c4562b4fe Mon Sep 17 00:00:00 2001
From: fabiotudone-da <fabio.tudone@digitalasset.com>
Date: Wed, 4 Mar 2020 08:18:05 +0100
Subject: [PATCH] Ensure `NodeInfo` derived properties `informeesOfNode` and
 `requireAuthorizers` always return (#4554)

Fail with a more explanatory message if `Fetch.actingParties` is `None`

CHANGELOG_BEGIN
CHANGELOG_END
---
 .../digitalasset/daml/lf/transaction/NodeInfo.scala   | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/daml-lf/transaction/src/main/scala/com/digitalasset/daml/lf/transaction/NodeInfo.scala b/daml-lf/transaction/src/main/scala/com/digitalasset/daml/lf/transaction/NodeInfo.scala
index 5a2bd54590..07e0997096 100644
--- a/daml-lf/transaction/src/main/scala/com/digitalasset/daml/lf/transaction/NodeInfo.scala
+++ b/daml-lf/transaction/src/main/scala/com/digitalasset/daml/lf/transaction/NodeInfo.scala
@@ -49,8 +49,15 @@ object NodeInfo {
     def stakeholders: Set[Party]
     def actingParties: Option[Set[Party]]
 
-    final def requiredAuthorizers: Set[Party] = actingParties.get
-    final def informeesOfNode: Set[Party] = signatories | actingParties.get
+    final def requiredAuthorizers: Set[Party] =
+      actingPartiesOrThrow
+    final def informeesOfNode: Set[Party] =
+      signatories | actingPartiesOrThrow
+
+    private[this] def actingPartiesOrThrow: Set[Party] =
+      actingParties.fold(
+        throw new IllegalStateException(
+          "'Fetch.actingParties' should always be present but is 'None'"))(identity)
   }
 
   trait Exercise extends NodeInfo {