From ca3128f44c195e68a108c3bf870c59efe471cc64 Mon Sep 17 00:00:00 2001
From: Dimos Raptis <dimos.raptis@r3.com>
Date: Mon, 28 Oct 2019 16:01:30 +0000
Subject: [PATCH] Add check in transaction builder

---
 .../corda/core/transactions/TransactionBuilder.kt   | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/core/src/main/kotlin/net/corda/core/transactions/TransactionBuilder.kt b/core/src/main/kotlin/net/corda/core/transactions/TransactionBuilder.kt
index c31011e51f..93fd289bca 100644
--- a/core/src/main/kotlin/net/corda/core/transactions/TransactionBuilder.kt
+++ b/core/src/main/kotlin/net/corda/core/transactions/TransactionBuilder.kt
@@ -285,7 +285,9 @@ open class TransactionBuilder(
         // For each contract, resolve the AutomaticPlaceholderConstraint, and select the attachment.
         val contractAttachmentsAndResolvedOutputStates: List<Pair<AttachmentId, List<TransactionState<ContractState>>?>> = allContracts.toSet()
                 .map { ctr ->
-                    handleContract(ctr, inputContractGroups[ctr], outputContractGroups[ctr], explicitAttachmentContractsMap[ctr], services)
+                    handleContract(ctr, inputContractGroups[ctr], outputContractGroups[ctr], explicitAttachmentContractsMap[ctr], services).also {
+                        it.second?.forEach { state -> checkForUnsupportedConstraints(state, services) }
+                    }
                 }
 
         val resolvedStates: List<TransactionState<ContractState>> = contractAttachmentsAndResolvedOutputStates.mapNotNull { it.second }
@@ -433,6 +435,15 @@ open class TransactionBuilder(
         return Pair(selectedAttachmentId, resolvedOutputStates)
     }
 
+    private fun checkForUnsupportedConstraints(transactionState: TransactionState<ContractState>, services: ServicesForResolution) {
+        if (transactionState.constraint is SignatureAttachmentConstraint) {
+            val constraintKey = transactionState.constraint.key
+            if (constraintKey is CompositeKey && constraintKey.leafKeys.size > 1)
+                checkMinimumPlatformVersion(services.networkParameters.minimumPlatformVersion, 5,
+                        "Composite keys for signature constraints")
+        }
+    }
+
     /**
      * Checks whether the current transaction can migrate from a [HashAttachmentConstraint] to a
      * [SignatureAttachmentConstraint]. This is only possible in very specific scenarios. Most