Removed references to certain parts of BsonDefaults.

Author: papafe

src/MongoDB.Bson/BsonDefaults.cs

@@ -43,6 +43,12 @@ public static IBsonSerializer DynamicDocumentSerializer
             set => BsonSerializer.DefaultSerializationDomain.BsonDefaults.DynamicDocumentSerializer = value;
         }
 
+        /* QUESTION How do we do with those two? I don't think I can remove references to them without breaking public API.
+         * We should modify the API to have those two values (in the writer/reader settings where they are used) be nullable.
+         * The problem is that we need to now when these values have been set externally or not. If they have not, then they should
+         * be retrieved from the closest domain. We could use a negative sentinel value for that, but that would not be the best.
+         */
+
         /// <summary>
         /// Gets or sets the default max document size. The default is 4MiB.
         /// </summary>

src/MongoDB.Bson/BsonDefaultsDomain.cs

@@ -19,7 +19,7 @@
 
 namespace MongoDB.Bson
 {
-    internal class BsonDefaultsDomain : IBsonDefaults  //TODO This will need to be public at a later point
+    internal class BsonDefaultsDomain : IBsonDefaults
     {
         private IBsonSerializationDomain _serializationDomain;
         private bool _dynamicArraySerializerWasSet;

src/MongoDB.Bson/Serialization/BsonDeserializationContext.cs

@@ -48,6 +48,9 @@ private BsonDeserializationContext(
             }
 
             _serializationDomain ??= BsonSerializer.DefaultSerializationDomain;
+
+            _dynamicArraySerializer ??= _serializationDomain.BsonDefaults.DynamicArraySerializer;
+            _dynamicDocumentSerializer ??= _serializationDomain.BsonDefaults.DynamicDocumentSerializer;
         }
 
         // public properties
@@ -167,11 +170,10 @@ internal Builder(BsonDeserializationContext other, IBsonReader reader)
                     _dynamicArraySerializer = other.DynamicArraySerializer;
                     _dynamicDocumentSerializer = other.DynamicDocumentSerializer;
                 }
-                else
-                {
-                    _dynamicArraySerializer = BsonDefaults.DynamicArraySerializer;
-                    _dynamicDocumentSerializer = BsonDefaults.DynamicDocumentSerializer;
-                }
+
+                /* QUESTION I removed the part where we set the dynamic serializers from the BsonDefaults, and delay it until we have a serialization domain (when we build the DeserializationContext).
+                 * This is technically changing the public behaviour, but it's in a builder, I do not thing it will affect anyone. Same done for the serialization context.
+                 */
             }
 
             // properties

src/MongoDB.Bson/Serialization/BsonSerializationContext.cs

@@ -36,6 +36,10 @@ private BsonSerializationContext(
             _writer = writer;
             _isDynamicType = isDynamicType;
             _serializationDomain = writer.Settings?.SerializationDomain ?? BsonSerializer.DefaultSerializationDomain;
+
+            _isDynamicType??= t =>
+                (_serializationDomain.BsonDefaults.DynamicArraySerializer != null && t == _serializationDomain.BsonDefaults.DynamicArraySerializer.ValueType) ||
+                (_serializationDomain.BsonDefaults.DynamicDocumentSerializer != null && t == _serializationDomain.BsonDefaults.DynamicDocumentSerializer.ValueType);
         }
 
         // public properties
@@ -126,12 +130,10 @@ internal Builder(BsonSerializationContext other, IBsonWriter writer)
                 {
                     _isDynamicType = other._isDynamicType;
                 }
-                else
-                {
-                    _isDynamicType = t =>
-                        (BsonDefaults.DynamicArraySerializer != null && t == BsonDefaults.DynamicArraySerializer.ValueType) ||
-                        (BsonDefaults.DynamicDocumentSerializer != null && t == BsonDefaults.DynamicDocumentSerializer.ValueType);
-                }
+
+                /* QUESTION I removed the part where we set _isDynamicType from the BsonDefaults, and delay it until we have a serialization domain (when we build the SerializationContext).
+                 * This is technically changing the public behaviour, but it's in a builder, I do not thing it will affect anyone. Same done for the deserialization context.
+                 */
             }
 
             // properties

src/MongoDB.Driver/Core/WireProtocol/Messages/Encoders/BinaryEncoders/ClientBulkWriteOpsSectionFormatter.cs

@@ -63,7 +63,7 @@ public void FormatSection(ClientBulkWriteOpsCommandMessageSection section, IBson
                 throw new ArgumentException("Writer must be an instance of BsonBinaryWriter.");
             }
 
-            _serializerRegistry = BsonSerializer.SerializerRegistry;
+            _serializerRegistry = BsonSerializer.SerializerRegistry; //FP This needs to go
             var serializationContext = BsonSerializationContext.CreateRoot(binaryWriter);
             _idsMap = section.IdsMap;
             var stream = binaryWriter.BsonStream;