From eb318756ff62879c6a9efabf5e2145c241c1a975 Mon Sep 17 00:00:00 2001
From: Francesco Mazzoli <francesco.mazzoli@digitalasset.com>
Date: Mon, 8 Apr 2019 11:59:49 +0200
Subject: [PATCH] decode key expressions in scala correctly. fixes #177 (#214)

* decode key expressions in scala correctly. fixes #177

replaced a `foldRight` with a `foldLeft`, projections were decoded
backwards.

* remove ContractKeysSimple -- superseded by ContractKeys
---
 .../daml-ghc/tests/ContractKeys.daml          |  2 -
 .../daml-ghc/tests/ContractKeysSimple.daml    | 51 -------------------
 .../daml/lf/lfpackage/DecodeV1.scala          |  4 +-
 3 files changed, 2 insertions(+), 55 deletions(-)
 delete mode 100644 daml-foundations/daml-ghc/tests/ContractKeysSimple.daml

diff --git a/daml-foundations/daml-ghc/tests/ContractKeys.daml b/daml-foundations/daml-ghc/tests/ContractKeys.daml
index 2366392886..754a73816f 100644
--- a/daml-foundations/daml-ghc/tests/ContractKeys.daml
+++ b/daml-foundations/daml-ghc/tests/ContractKeys.daml
@@ -1,9 +1,7 @@
 -- Check that the compiler bits of contract keys work.
--- @TODO (#177): Fix the engine such that this test passes. Remove `ContractKeysSimple.daml` when it does.
 -- @IGNORE-LF 1.0
 -- @IGNORE-LF 1.1
 -- @IGNORE-LF 1.2
--- @ERROR CRASH: RecProj on non-record
 daml 1.2
 module ContractKeys where
 
diff --git a/daml-foundations/daml-ghc/tests/ContractKeysSimple.daml b/daml-foundations/daml-ghc/tests/ContractKeysSimple.daml
deleted file mode 100644
index 9c836aeef7..0000000000
--- a/daml-foundations/daml-ghc/tests/ContractKeysSimple.daml
+++ /dev/null
@@ -1,51 +0,0 @@
--- Check that the compiler bits of contract keys work.
--- @TODO (#177): Remove this test when #177 has been fixed.
--- @IGNORE-LF 1.0
--- @IGNORE-LF 1.1
--- @IGNORE-LF 1.2
-daml 1.2
-module ContractKeysSimple where
-
-template AccountInvitation with
-    account : Account
-  where
-    signatory account.bank
-
-    controller account.accountHolder can
-      Accept : ContractId Account
-        do create account
-
-template Account with
-    bank : Party
-    accountHolder : Party
-    accountCode : Text
-    accountNumber : Int
-  where
-    signatory [bank, accountHolder]
-
-instance Key Account (Party, Text, Int) where
-    key acc = (acc.bank, acc.accountCode, acc.accountNumber)
-    keyMaintainers Proxy (bank, _, _) = [bank]
-
-test = scenario do
-    bank <- getParty "Bank"
-    alice <- getParty "Alice"
-    let account = Account with
-            bank
-            accountHolder = alice
-            accountCode = "CH"
-            accountNumber = 123
-    let accountKey = (bank, "CH", 123)
-    invitationCid <- submit bank do
-        create AccountInvitation with account
-    accountCid <- submit alice do
-        exercise invitationCid Accept
-
-    accountCid' <- submit bank do
-        lookupByKey accountKey
-    assert $ accountCid' == Some accountCid
-
-    (accountCid', account') <- submit bank do
-        fetchByKey accountKey
-    assert $ accountCid' == accountCid
-    assert $ account' == account
diff --git a/daml-lf/lfpackage/src/main/scala/com/digitalasset/daml/lf/lfpackage/DecodeV1.scala b/daml-lf/lfpackage/src/main/scala/com/digitalasset/daml/lf/lfpackage/DecodeV1.scala
index d110bf9a08..0154b3cd77 100644
--- a/daml-lf/lfpackage/src/main/scala/com/digitalasset/daml/lf/lfpackage/DecodeV1.scala
+++ b/daml-lf/lfpackage/src/main/scala/com/digitalasset/daml/lf/lfpackage/DecodeV1.scala
@@ -164,8 +164,8 @@ private[lf] class DecodeV1(minor: LanguageMinorVersion) extends Decode.OfPackage
 
         case PLF.KeyExpr.SumCase.PROJECTIONS =>
           val lfProjs = expr.getProjections.getProjectionsList.asScala
-          (lfProjs :\ (EVar(tplVar): Expr)) {
-            case (lfProj, acc) =>
+          lfProjs.foldLeft(EVar(tplVar): Expr) {
+            case (acc, lfProj) =>
               ERecProj(decodeTypeConApp(lfProj.getTycon), lfProj.getField, acc)
           }