fix(ledger) tx reversion handles empty middle accounts

internal/controller/ledger/controller_default.go

@@ -406,6 +406,13 @@ func (ctrl *DefaultController) revertTransaction(ctx context.Context, store Stor
 				balances[posting.Source][posting.Asset],
 				big.NewInt(0).Neg(posting.Amount),
 			)
+			if _, ok := balances[posting.Destination]; ok {
+				// if destination is also a source in some posting, since balances should only contain posting sources
+				balances[posting.Destination][posting.Asset] = balances[posting.Destination][posting.Asset].Add(
+					balances[posting.Destination][posting.Asset],
+					posting.Amount,
+				)
+			}
 		}
 
 		for account, forAccount := range balances {

test/e2e/api_transactions_revert_test.go

@@ -219,4 +219,66 @@ var _ = Context("Ledger revert transactions API tests", func() {
 			})
 		})
 	})
+	When("creating a transaction through an empty passthrough account", func() {
+		var (
+			timestamp = time.Now().Round(time.Second).UTC()
+			tx        *components.V2Transaction
+			events    chan *nats.Msg
+			err       error
+		)
+		BeforeEach(func() {
+			events = Subscribe(GinkgoT(), testServer.GetValue())
+			tx, err = CreateTransaction(
+				ctx,
+				testServer.GetValue(),
+				operations.V2CreateTransactionRequest{
+					V2PostTransaction: components.V2PostTransaction{
+						Metadata: map[string]string{},
+						Postings: []components.V2Posting{
+							{
+								Amount:      big.NewInt(100),
+								Asset:       "USD",
+								Source:      "walter",
+								Destination: "wendy",
+							},
+							{
+								Amount:      big.NewInt(100),
+								Asset:       "USD",
+								Source:      "wendy",
+								Destination: "world",
+							}
+						},
+						Timestamp: &timestamp,
+					},
+					Ledger: "default",
+				},
+			)
+			Expect(err).ToNot(HaveOccurred())
+		})
+		When("trying to revert the passthrough transaction", func() {
+			_, err := RevertTransaction(
+				ctx,
+				testServer.GetValue(),
+				operations.V2RevertTransactionRequest{
+					Ledger:          "default",
+					ID:              tx.ID,
+					AtEffectiveDate: pointer.For(true),
+				},
+			)
+			Expect(err).To(Succeed())
+		})
+		It("should revert the passthrough transaction at date of the original tx", func() {
+			response, err := GetTransaction(
+				ctx,
+				testServer.GetValue(),
+				operations.V2GetTransactionRequest{
+					Ledger: "default",
+					ID:     tx.ID,
+				},
+			)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(response.Reverted).To(BeTrue())
+			Expect(response.Timestamp).To(Equal(tx.Timestamp))
+		})
+	})
 })