protobuf-net

• add UAP TFM

• IMPORTANT fix #403 - key cache was incorrect in some cases involving multi-level inheritance; update from 2.3.8 or above is highly recommended

• fix #402 - zero decimal with non-trivial sign/scale should round-trip correctly
• fix additional scenarios for #401

• fix #401 - error introduced in the new key cache from v2.3.8

• fix #388 - stability when DynamicMethod is not available (UWP, iOS, etc)

• fix behaviour of DiscriminatedUnion* for None enum case

• speculative fix for iOS issues (#381)
• add discriminator accessor to discriminated union types, for protogen v1.0.6
• improve performance of ProtoWriter.DemandSpace (#378 from szehetner)
• protogen - better support for wildcard paths (#390 from RansomVO)
• fix #313 immutable arrays (#346 from BryantL)
• improve LOH behaviour (#307 from mintsoft)
• allow model precompilation for unknown types (#326 from daef)
• improve type-key lookup performance (#310 from alex-sherman)

• add .NET Standard 1.0 "profile 259" support - contributed by Lorick Russow

• add .NET Standard 2.0 build target

• add codegen support for C# 3.0; C# 6.0 is still the default, but can be overridden via CLI or .proto options; see #343
• updated Google "protoc" tooling on the web-site
• better exception messages when inheritance problems are detected; #186 via TrexinanF14
• add switch to allow the string cache code to be disabled; #333 via solyutor

• fix #341 - dictionaries with nullable types

• fix protogen bug with [DefaultValue] for enums not including the fully qualified name when required
• fix pathological memory usage bug with large buffers (int-overflow); many thanks to Mikhail Brinchuk

• fix bug with IgnoreListHandling not being respected for custom dictionary-like types (with "map" taking precedence)

• fix bug with optional being emitted for sub-types in proto3 schemas (#280)
• add setter to ValueMember.Name - in particular allows runtime enum name configuration (#281)
• fix bug with implicit map when TKey is an enum type (#289)
• fix build config (optimized build)

• include better information when rejecting jagged arrays / nested lists (SO 45062514)

• fix issue with "map" detection of complex dictionaries-of-arrays incorrectly trying to configure a MetaType for the array type

• fix issue with unwanted static constructors being detected (#276)
• explicitly prevent MetaType instances for arrays

• further reading
• proto2/proto3 DSL processing tools to make a resurgance; preview is available here
• proto3 schema generation
• full support for map<,>, Timestamp, Duration
• dictionaries are now "maps" by default - duplicated keys replace values rather than causing exceptions
• support for one-of
• enums are now "pass thru" whenever possible - unknown values will not normally cause exceptions (this indirectly fixes #260, but proto3 semantics was the motivation)
• various bug-fixes
• fix bug in schema output forn enums withut a zero value (#224)
• fix bug in runtime handling of immutable collections (#264)
• fix issue with serialization context being list (#268)
• fix issue with type error message when type is generic (#267)
• net20 / net35 targets reinstated for NuGet build (#262)
• fix for Uri handling (#162 / #261)
• fix: Type members should work with GetProto<T> (as string)

• critical bug fix #256 - length-based readers are failing; if you are using 2.2.0, please update as soon as possible (this bug was introduced in 2.2.0)
• fix #241 - check all callback parameters (signature validation)
• removed [Obsolete] markers left in place during 64-bit updates
• release string interner earlier (keeps a possibly-large array reachable)
• various documentation fixes (#184, #189, #216)

• enable 64-bit processing (2GiB+ file sizes) within constraints that no single sub-graph can exceed 2GiB; this is assisted by...
• new IsGroup property on [ProtoContract(...)] that indicates that a type should always be treated as a group (rather than having to specify "group" per-member); groups do not require length-prefix or buffering, so are trivially usable in huge files
• support get-only automatically-implemented properties (#188)
• support ValueTuple<...>
• fix bug with cyclic types resolving as lists (#167)
• optimized encoding of packed fixed-length primitives (in particular, arrays)

(see also: protobuf-net: large data, and the future)

• add support for custom static methods equivalent to static conversion operators, via [ProtoConverter]
• GetSchema: do not emit default values for non-optional members (#75)
• .NET Standard support
• protogen: allow use of native protoc; additional proto-path support (#119)
• protogen: fix name for getters and default value (#2)
• fix timeout issue on portable frameworks (#114)
• DateTime serialization can include DateTimeKind
• fix Uri serialization on PCLs (#98)
• documentation typos and tweaks (#99, #112)
• tupe serializer: fix issues with case sensitivity / i18n (#104)
• fix bug with returning empty byte arrays (#111)
• additional convenience Deserilize overload (#12)
• support serialization-context-aware callback methods

(baseline)