fix(api): treat empty-string events list as absent in shielded scan APIs

Author: Federico2014

framework/src/main/java/org/tron/core/services/RpcApiService.java

@@ -294,7 +294,7 @@ private StatusRuntimeException getRunTimeException(Exception e) {
 
   private static boolean rejectIfEventsPresent(
       StreamObserver<?> responseObserver, ProtocolStringList events) {
-    if (!events.isEmpty()) {
+    if (events.stream().anyMatch(s -> !s.isEmpty())) {
       responseObserver.onError(Status.INVALID_ARGUMENT
           .withDescription("'events' field is deprecated and no longer supported")
           .asRuntimeException());

framework/src/main/java/org/tron/core/services/http/ScanShieldedTRC20NotesByIvkServlet.java

@@ -39,7 +39,7 @@ public static String convertOutput(GrpcAPI.DecryptNotesTRC20 notes, boolean visi
   }
 
   static void rejectIfEventsPresent(ProtocolStringList events) {
-    if (!events.isEmpty()) {
+    if (events.stream().anyMatch(s -> !s.isEmpty())) {
       throw new IllegalArgumentException(EVENTS_DEPRECATED_MSG);
     }
   }

framework/src/test/java/org/tron/core/services/http/ScanShieldedTRC20NotesServletTest.java

@@ -74,4 +74,44 @@ public void testOvkGetRejectsDeprecatedEvents() throws Exception {
     Assert.assertTrue(response.getContentAsString().contains(EVENTS_DEPRECATED_MSG));
   }
 
+  @Test
+  public void testIvkPostEmptyEventsPassesGuard() throws Exception {
+    MockHttpServletRequest request = createRequest(HttpPost.METHOD_NAME);
+    request.setContentType("application/json");
+    request.setContent("{\"events\":[\"\"]}".getBytes(UTF_8));
+    MockHttpServletResponse response = new MockHttpServletResponse();
+    scanShieldedTRC20NotesByIvkServlet.doPost(request, response);
+    Assert.assertNotEquals(HttpServletResponse.SC_BAD_REQUEST, response.getStatus());
+  }
+
+  @Test
+  public void testOvkPostEmptyEventsPassesGuard() throws Exception {
+    MockHttpServletRequest request = createRequest(HttpPost.METHOD_NAME);
+    request.setContentType("application/json");
+    request.setContent("{\"events\":[\"\"]}".getBytes(UTF_8));
+    MockHttpServletResponse response = new MockHttpServletResponse();
+    scanShieldedTRC20NotesByOvkServlet.doPost(request, response);
+    Assert.assertNotEquals(HttpServletResponse.SC_BAD_REQUEST, response.getStatus());
+  }
+
+  @Test
+  public void testIvkPostWithoutEventsPassesGuard() throws Exception {
+    MockHttpServletRequest request = createRequest(HttpPost.METHOD_NAME);
+    request.setContentType("application/json");
+    request.setContent("{\"start_block_index\":0,\"end_block_index\":1}".getBytes(UTF_8));
+    MockHttpServletResponse response = new MockHttpServletResponse();
+    scanShieldedTRC20NotesByIvkServlet.doPost(request, response);
+    Assert.assertNotEquals(HttpServletResponse.SC_BAD_REQUEST, response.getStatus());
+  }
+
+  @Test
+  public void testOvkPostWithoutEventsPassesGuard() throws Exception {
+    MockHttpServletRequest request = createRequest(HttpPost.METHOD_NAME);
+    request.setContentType("application/json");
+    request.setContent("{\"start_block_index\":0,\"end_block_index\":1}".getBytes(UTF_8));
+    MockHttpServletResponse response = new MockHttpServletResponse();
+    scanShieldedTRC20NotesByOvkServlet.doPost(request, response);
+    Assert.assertNotEquals(HttpServletResponse.SC_BAD_REQUEST, response.getStatus());
+  }
+
 }