Fix #51

Author: Havret

src/Protobuf.System.Text.Json/ProtobufConverter.cs

@@ -90,7 +90,9 @@ private static Func<FieldDescriptor, string> GetConvertNameFunc(JsonNamingPolicy
 
             if (propertyName == null || !_fieldsLookup.TryGetValue(propertyName, out var fieldInfo))
             {
-                reader.Skip();
+                // We need to call TrySkip instead of Skip as Skip may throw exception when called in DeserializeAsync
+                // context https://github.com/dotnet/runtime/issues/39795
+                _ = reader.TrySkip();
                 continue;
             }
 

test/Protobuf.System.Text.Json.Tests/SchemaEvolutionTests.cs

@@ -1,5 +1,10 @@
-using System.Text.Json;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text.Json;
 using System.Text.Json.Protobuf.Tests;
+using System.Threading.Tasks;
 using Protobuf.System.Text.Json.Tests.Utils;
 using Shouldly;
 using Xunit;
@@ -29,4 +34,27 @@ public void Should_be_able_to_deserialize_array_of_schema_v2_to_array_of_schema_
         // Assert
         deserialized.ShouldHaveSingleItem();
     }
+    
+    [Fact]
+    public async Task Should_be_able_to_deserialize_array_of_schema_v2_to_array_of_schema_v1_when_schema_v2_has_additional_repeated_field_2()
+    {
+        // Arrange
+        var schemaEvolutionV2 = Enumerable.Range(0, 50_000).Select(x => new SchemaEvolutionV2
+        {
+            Property1 = x,
+            Property2 = {x + 1, x + 2}
+        }).ToList();
+
+        var jsonSerializerOptions = TestHelper.CreateJsonSerializerOptions();
+        using var memoryStream = new MemoryStream();
+        await JsonSerializer.SerializeAsync(memoryStream, schemaEvolutionV2, jsonSerializerOptions);
+        memoryStream.Position = 0;
+
+        // Act
+        var deserialized = JsonSerializer.Deserialize<SchemaEvolutionV1[]>(memoryStream, jsonSerializerOptions);
+
+        // Assert
+        deserialized.ShouldNotBeNull();
+        deserialized.Length.ShouldBe(schemaEvolutionV2.Count);
+    }
 }