From 9718602ce32d25b2d07e9cb9b3bcc7a5110e3ab4 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 11 Jan 2023 11:21:58 +0300
Subject: [PATCH 1/2] rpcsrv: return empty set from findstates when there is no
 data

Fix #2863.
---
 pkg/services/rpcsrv/server.go      |  4 ++--
 pkg/services/rpcsrv/server_test.go | 15 ++++++++++++++-
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/pkg/services/rpcsrv/server.go b/pkg/services/rpcsrv/server.go
index bcd89542a..71ed92cf6 100644
--- a/pkg/services/rpcsrv/server.go
+++ b/pkg/services/rpcsrv/server.go
@@ -1541,8 +1541,8 @@ func (s *Server) findStates(ps params.Params) (interface{}, *neorpc.Error) {
 	}
 	pKey := makeStorageKey(cs.ID, prefix)
 	kvs, err := s.chain.GetStateModule().FindStates(root, pKey, key, count+1) // +1 to define result truncation
-	if err != nil {
-		return nil, neorpc.NewInternalServerError(fmt.Sprintf("failed to find historical items: %s", err))
+	if err != nil && !errors.Is(err, mpt.ErrNotFound) {
+		return nil, neorpc.NewInternalServerError(fmt.Sprintf("failed to find state items: %s", err))
 	}
 	res := result.FindStates{}
 	if len(kvs) == count+1 {
diff --git a/pkg/services/rpcsrv/server_test.go b/pkg/services/rpcsrv/server_test.go
index a6851a841..7841c4828 100644
--- a/pkg/services/rpcsrv/server_test.go
+++ b/pkg/services/rpcsrv/server_test.go
@@ -2123,7 +2123,9 @@ func testRPCProtocol(t *testing.T, doRPCCall func(string, string, *testing.T) []
 				require.NoError(t, json.Unmarshal(rawRes, vp))
 				require.Equal(t, value, vp.Value)
 			}
-			checkProof(t, actual.FirstProof, actual.Results[0].Value)
+			if len(actual.Results) > 0 {
+				checkProof(t, actual.FirstProof, actual.Results[0].Value)
+			}
 			if len(actual.Results) > 1 {
 				checkProof(t, actual.LastProof, actual.Results[len(actual.Results)-1].Value)
 			}
@@ -2157,6 +2159,17 @@ func testRPCProtocol(t *testing.T, doRPCCall func(string, string, *testing.T) []
 				Truncated: false,
 			})
 		})
+		t.Run("good: empty prefix, no limit, no data", func(t *testing.T) {
+			// empty prefix should be considered as no prefix specified.
+			root, err := e.chain.GetStateModule().GetStateRoot(20)
+			require.NoError(t, err)
+			stdHash, _ := e.chain.GetNativeContractScriptHash(nativenames.StdLib) // It has no data.
+			params := fmt.Sprintf(`"%s", "%s", ""`, root.Root.StringLE(), stdHash.StringLE())
+			testFindStates(t, params, root.Root, result.FindStates{
+				Results:   []result.KeyValue{},
+				Truncated: false,
+			})
+		})
 		t.Run("good: with prefix, no limit", func(t *testing.T) {
 			// pairs for this test where put to the contract storage at block #16
 			root, err := e.chain.GetStateModule().GetStateRoot(16)

From e780037cb4e361fcc9c477cd2a073b4bfb2d5797 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 11 Jan 2023 11:23:47 +0300
Subject: [PATCH 2/2] rpcsrv: use valid stateroot hash in failing tests

Just in case.
---
 pkg/services/rpcsrv/server_test.go | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/pkg/services/rpcsrv/server_test.go b/pkg/services/rpcsrv/server_test.go
index 7841c4828..08d636d07 100644
--- a/pkg/services/rpcsrv/server_test.go
+++ b/pkg/services/rpcsrv/server_test.go
@@ -472,22 +472,22 @@ var rpcTestCases = map[string][]rpcTestCase{
 		},
 		{
 			name:   "invalid contract",
-			params: `["0000000000000000000000000000000000000000000000000000000000000000", "0xabcdef"]`,
+			params: `["` + block20StateRootLE + `", "0xabcdef"]`,
 			fail:   true,
 		},
 		{
 			name:   "invalid prefix",
-			params: `["0000000000000000000000000000000000000000000000000000000000000000", "` + testContractHash + `", "notabase64%"]`,
+			params: `["` + block20StateRootLE + `", "` + testContractHash + `", "notabase64%"]`,
 			fail:   true,
 		},
 		{
 			name:   "invalid key",
-			params: `["0000000000000000000000000000000000000000000000000000000000000000", "` + testContractHash + `", "QQ==", "notabase64%"]`,
+			params: `["` + block20StateRootLE + `", "` + testContractHash + `", "QQ==", "notabase64%"]`,
 			fail:   true,
 		},
 		{
 			name:   "unknown contract/large count",
-			params: `["0000000000000000000000000000000000000000000000000000000000000000", "0000000000000000000000000000000000000000", "QQ==", "QQ==", 101]`,
+			params: `["` + block20StateRootLE + `", "0000000000000000000000000000000000000000", "QQ==", "QQ==", 101]`,
 			fail:   true,
 		},
 	},