2022-03-25 version 3.20.0 (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)

Ruby

• Dropped Ruby 2.3 and 2.4 support for CI and releases. (#9311)
• Added Ruby 3.1 support for CI and releases (#9566).
• Message.decode/encode: Add recursion_limit option (#9218/#9486)
• Allocate with xrealloc()/xfree() so message allocation is visible to the Ruby GC. In certain tests this leads to much lower memory usage due to more frequent GC runs (#9586).
• Fix conversion of singleton classes in Ruby (#9342)
• Suppress warning for intentional circular require (#9556)
• JSON will now output shorter strings for double and float fields when possible without losing precision.
• Encoding and decoding of binary format will now work properly on big-endian systems.
• UTF-8 verification was fixed to properly reject surrogate code points.
• Unknown enums for proto2 protos now properly implement proto2's behavior of putting such values in unknown fields.

Java

• Revert "Standardize on Array copyOf" (#9400)
• Resolve more java field accessor name conflicts (#8198)
• Don't support map fields in DynamicMessage.Builder.{getFieldBuilder,getRepeatedFieldBuilder}
• Fix parseFrom to only throw InvalidProtocolBufferException
• InvalidProtocolBufferException now allows arbitrary wrapped Exception types.
• Fix bug in FieldSet.Builder.mergeFrom
• Flush CodedOutputStream also flushes underlying OutputStream
• When oneof case is the same and the field type is Message, merge the subfield. (previously it was replaced.)’
• Add @CheckReturnValue to some protobuf types
• Report original exceptions when parsing JSON
• Add more info to @deprecated javadoc for set/get/has methods
• Fix initialization bug in doc comment line numbers
• Fix comments for message set wire format.

Kotlin

• Add test scope to kotlin-test for protobuf-kotlin-lite (#9518)
• Add orNull extensions for optional message fields.
• Add orNull extensions to all proto3 message fields.

Python

• Dropped support for Python < 3.7 (#9480)
• Protoc is now able to generate python stubs (.pyi) with --pyi_out
• Pin multibuild scripts to get manylinux1 wheels back (#9216)
• Fix type annotations of some Duration and Timestamp methods.
• Repeated field containers are now generic in field types and could be used in type annotations. *[Breaking change] Protobuf python generated codes are simplified. Descriptors and message classes' definitions are now dynamic created in internal/builder.py. Insertion Points for messages classes are discarded.
• has_presence is added for FieldDescriptor in python
• Loosen indexing type requirements to allow valid index() implementations rather than only PyLongObjects.
• Fix the deepcopy bug caused by not copying message_listener.
• Added python JSON parse recursion limit (default 100)
• Path info is added for python JSON parse errors
• Pure python repeated scalar fields will not able to pickle. Convert to list first.
• Timestamp.ToDatetime() now accepts an optional tzinfo parameter. If specified, the function returns a timezone-aware datetime in the given time zone. If omitted or None, the function returns a timezone-naive UTC datetime (as previously).
• Adds client_streaming and server_streaming fields to MethodDescriptor.
• Add "ensure_ascii" parameter to json_format.MessageToJson. This allows smaller JSON serializations with UTF-8 or other non-ASCII encodings.
• Added experimental support for directly assigning numpy scalars and array.
• Improve the calculation of public_dependencies in DescriptorPool.
• [Breaking Change] Disallow setting fields to numpy singleton arrays or repeated fields to numpy multi-dimensional arrays. Numpy arrays should be indexed or flattened explicitly before assignment.

Compiler

• Migrate IsDefault(const std::string*) and UnsafeSetDefault(const std::string*)
• Implement strong qualified tags for TaggedPtr
• Rework allocations to power-of-two byte sizes.
• Migrate IsDefault(const std::string*) and UnsafeSetDefault(const std::string*)
• Implement strong qualified tags for TaggedPtr
• Make TaggedPtr Set...() calls explicitly spell out the content type.
• Check for parsing error before verifying UTF8.
• Enforce a maximum message nesting limit of 32 in the descriptor builder to guard against stack overflows
• Fixed bugs in operators for RepeatedPtrIterator
• Assert a maximum map alignment for allocated values
• Fix proto1 group extension protodb parsing error
• Do not log/report the same descriptor symbol multiple times if it contains more than one invalid character.
• Add UnknownFieldSet::SerializeToString and SerializeToCodedStream.
• Remove explicit default pointers and deprecated API from protocol compiler

Arenas

• Change Repeated*Field to reuse memory when using arenas.
• Implements pbarenaz for profiling proto arenas
• Introduce CreateString() and CreateArenaString() for cleaner semantics
• Fix unreferenced parameter for MSVC builds
• Add UnsafeSetAllocated to be used for one-of string fields.
• Make Arena::AllocateAligned() a public function.
• Determine if ArenaDtor related code generation is necessary in one place.
• Implement on demand register ArenaDtor for InlinedStringField

C++

• Enable testing via CTest (#8737)
• Add option to use external GTest in CMake (#8736)
• CMake: Set correct sonames for libprotobuf-lite.so and libprotoc.so (#8635) (#9529)
• Add cmake option protobuf_INSTALL to not install files (#7123)
• CMake: Allow custom plugin options e.g. to generate mocks (#9105)
• CMake: Use linker version scripts (#9545)
• Manually *struct Cord fields to work better with arenas.
• Manually destruct map fields.
• Generate narrower code
• Fix https://github.com/protocolbuffers/protobuf/issues/9378 by removing shadowed cached_size field
• Remove GetPointer() and explicit nullptr defaults.
• Add proto_h flag for speeding up large builds
• Add missing overload for reference wrapped fields.
• Add MergedDescriptorDatabase::FindAllFileNames()
• RepeatedField now defines an iterator type instead of using a pointer.
• Remove obsolete macros GOOGLE_PROTOBUF_HAS_ONEOF and GOOGLE_PROTOBUF_HAS_ARENAS.

PHP

• Fix: add missing reserved classnames (#9458)
• PHP 8.1 compatibility (#9370)

C#

• Fix trim warnings (#9182)
• Fixes NullReferenceException when accessing FieldDescriptor.IsPacked (#9430)
• Add ToProto() method to all descriptor classes (#9426)
• Add an option to preserve proto names in JsonFormatter (#6307)

Objective-C

• Add prefix_to_proto_package_mappings_path option. (#9498)
• Rename proto_package_to_prefix_mappings_path to package_to_prefix_mappings_path. (#9552)
• Add a generation option to control use of forward declarations in headers. (#9568)

Ruby

• to_json will now use fewer decimal places to encode float/double in some cases, if the extra digits are not necessary for round-tripping

PHP

• to_json will now use fewer decimal places to encode float/double in some cases, if the extra digits are not necessary for round-tripping

Ruby

• Dropped Ruby 2.3 and 2.4 support for CI and releases. (#9311)
• Message.decode/encode: Add max_recursion_depth option (#9218)
• Rename max_recursion_depth to recursion_limit (#9486)
• Fix conversion of singleton classes in Ruby (#9342)
• Suppress warning for intentional circular require (#9556)
• JSON will now output shorter strings for double and float fields when possible without losing precision.
• Encoding and decoding of binary format will now work properly on big-endian systems.
• UTF-8 verification was fixed to properly reject surrogate code points.
• Unknown enums for proto2 protos now properly implement proto2's behavior of putting such values in unknown fields.

Java

• Revert "Standardize on Array copyOf" (#9400)
• Resolve more java field accessor name conflicts (#8198)
• Don't support map fields in DynamicMessage.Builder.{getFieldBuilder,getRepeatedFieldBuilder}
• Fix parseFrom to only throw InvalidProtocolBufferException
• InvalidProtocolBufferException now allows arbitrary wrapped Exception types.
• Fix bug in FieldSet.Builder.mergeFrom
• Flush CodedOutputStream also flushes underlying OutputStream
• When oneof case is the same and the field type is Message, merge the subfield. (previously it was replaced.)’
• Add @CheckReturnValue to some protobuf types
• Report original exceptions when parsing JSON
• Add more info to @deprecated javadoc for set/get/has methods
• Fix initialization bug in doc comment line numbers
• Fix comments for message set wire format.

Kotlin

• Add test scope to kotlin-test for protobuf-kotlin-lite (#9518)
• Add orNull extensions for optional message fields.
• Add orNull extensions to all proto3 message fields.

Python

• Dropped support for Python < 3.7 (#9480)
• Protoc is now able to generate python stubs (.pyi) with --pyi_out
• Pin multibuild scripts to get manylinux1 wheels back (#9216)
• Fix type annotations of some Duration and Timestamp methods.
• Repeated field containers are now generic in field types and could be used in type annotations.
• Protobuf python generated codes are simplified. Descriptors and message classes' definitions are now dynamic created in internal/builder.py. Insertion Points for messages classes are discarded.
• has_presence is added for FieldDescriptor in python
• Loosen indexing type requirements to allow valid index() implementations rather than only PyLongObjects.
• Fix the deepcopy bug caused by not copying message_listener.
• Added python JSON parse recursion limit (default 100)
• Path info is added for python JSON parse errors
• Pure python repeated scalar fields will not able to pickle. Convert to list first.
• Timestamp.ToDatetime() now accepts an optional tzinfo parameter. If specified, the function returns a timezone-aware datetime in the given time zone. If omitted or None, the function returns a timezone-naive UTC datetime (as previously).
• Adds client_streaming and server_streaming fields to MethodDescriptor.
• Add "ensure_ascii" parameter to json_format.MessageToJson. This allows smaller JSON serializations with UTF-8 or other non-ASCII encodings.
• Added experimental support for directly assigning numpy scalars and array.
• Improve the calculation of public_dependencies in DescriptorPool.
• [Breaking Change] Disallow setting fields to numpy singleton arrays or repeated fields to numpy multi-dimensional arrays. Numpy arrays should be indexed or flattened explicitly before assignment.

Compiler

• Migrate IsDefault(const std::string*) and UnsafeSetDefault(const std::string*)
• Implement strong qualified tags for TaggedPtr
• Rework allocations to power-of-two byte sizes.
• Migrate IsDefault(const std::string*) and UnsafeSetDefault(const std::string*)
• Implement strong qualified tags for TaggedPtr
• Make TaggedPtr Set...() calls explicitly spell out the content type.
• Check for parsing error before verifying UTF8.
• Enforce a maximum message nesting limit of 32 in the descriptor builder to guard against stack overflows
• Fixed bugs in operators for RepeatedPtrIterator
• Assert a maximum map alignment for allocated values
• Fix proto1 group extension protodb parsing error
• Do not log/report the same descriptor symbol multiple times if it contains more than one invalid character.
• Add UnknownFieldSet::SerializeToString and SerializeToCodedStream.
• Remove explicit default pointers and deprecated API from protocol compiler

Arenas

• Change Repeated*Field to reuse memory when using arenas.
• Implements pbarenaz for profiling proto arenas
• Introduce CreateString() and CreateArenaString() for cleaner semantics
• Fix unreferenced parameter for MSVC builds
• Add UnsafeSetAllocated to be used for one-of string fields.
• Make Arena::AllocateAligned() a public function.
• Determine if ArenaDtor related code generation is necessary in one place.
• Implement on demand register ArenaDtor for InlinedStringField

C++

• Enable testing via CTest (#8737)
• Add option to use external GTest in CMake (#8736)
• CMake: Set correct sonames for libprotobuf-lite.so and libprotoc.so (#8635) (#9529)
• Add cmake option protobuf_INSTALL to not install files (#7123)
• CMake: Allow custom plugin options e.g. to generate mocks (#9105)
• CMake: Use linker version scripts (#9545)
• Manually *struct Cord fields to work better with arenas.
• Manually destruct map fields.
• Generate narrower code
• Fix https://github.com/protocolbuffers/protobuf/issues/9378 by removing shadowed cached_size field
• Remove GetPointer() and explicit nullptr defaults.
• Add proto_h flag for speeding up large builds
• Add missing overload for reference wrapped fields.
• Add MergedDescriptorDatabase::FindAllFileNames()
• RepeatedField now defines an iterator type instead of using a pointer.
• Remove obsolete macros GOOGLE_PROTOBUF_HAS_ONEOF and GOOGLE_PROTOBUF_HAS_ARENAS.

PHP

• Fix: add missing reserved classnames (#9458)

C#

• Fix trim warnings (#9182)
• Fixes NullReferenceException when accessing FieldDescriptor.IsPacked (#9430)
• Add ToProto() method to all descriptor classes (#9426)
• Add an option to preserve proto names in JsonFormatter (#6307)

Objective-C

• Add prefix_to_proto_package_mappings_path option. (#9498)
• Rename proto_package_to_prefix_mappings_path to package_to_prefix_mappings_path. (#9552)
• Add a generation option to control use of forward declarations in headers. (#9568)

Java

• Refactoring java full runtime to reuse sub-message builders and prepare to migrate parsing logic from parse constructor to builder.
• Move proto wireformat parsing functionality from the private "parsing constructor" to the Builder class.
• Change the Lite runtime to prefer merging from the wireformat into mutable messages rather than building up a new immutable object before merging. This way results in fewer allocations and copy operations.
• Make message-type extensions merge from wire-format instead of building up instances and merging afterwards. This has much better performance.
• Fix TextFormat parser to build up recurring (but supposedly not repeated) sub-messages directly from text rather than building a new sub-message and merging the fully formed message into the existing field.
• This release addresses a Security Advisory for Java users

C++

• Reduce memory consumption of MessageSet parsing
• This release addresses a Security Advisory for C++ and Python users

Python

• Make libprotobuf symbols local on OSX to fix issue #9395 (#9435)

Ruby

• Fixed a data loss bug that could occur when the number of optional fields in a message is an exact multiple of 32. (#9440).

PHP

• Fixed a data loss bug that could occur when the number of optional fields in a message is an exact multiple of 32. (#9440).

Python

• Fix missing Windows wheel for Python 3.10 on PyPI

Java

• Improve performance characteristics of UnknownFieldSet parsing (#9371)
• This release addresses a Security Advisory for Java users

Bazel

• Ensure that release archives contain everything needed for Bazel (#9131)
• Align dependency handling with Bazel best practices (#9165)

JavaScript

• Fix ReferenceError: window is not defined when getting the global object (#9156)

Ruby

• Fix memory leak in MessageClass.encode (#9150)

C++

• Make proto2::Message::DiscardUnknownFields() non-virtual
• Separate RepeatedPtrField into its own header file
• For default floating point values of 0, consider all bits significant
• cmake: support MSVC_RUNTIME_LIBRARY property (#8851)
• Fix shadowing warnings (#8926)
• Fix for issue #8484, constant initialization doesn't compile in msvc clang-cl environment (#8993)
• Fix build on AIX and SunOS (#8373) (#9065)
• Add Android stlport and default toolchains to BUILD. (#8290)

Java

• For default floating point values of 0, consider all bits significant
• Annotate //java/com/google/protobuf/util/... with nullness annotations
• Use ArrayList copy constructor (#7853)

Kotlin

• Switch Kotlin proto DSLs to be implemented with inline value classes
• Fixing inlining and deprecation for repeated string fields (#9120)

Python

• Proto2 DecodeError now includes message name in error message
• Make MessageToDict convert map keys to strings (#8122)
• Add python-requires in setup.py (#8989)
• Add python 3.10 (#9034)

JavaScript

• Skip exports if not available by CommonJS (#8856)
• JS: Comply with CSP no-unsafe-eval. (#8864)

PHP

• Added "object" as a reserved name for PHP (#8962)

Ruby

• Override Map.clone to use Map's dup method (#7938)
• Ruby: build extensions for arm64-darwin (#8232)
• Add class method Timestamp.from_time to ruby well known types (#8562)
• Adopt pure ruby DSL implementation for JRuby (#9047)
• Add size to Map class (#8068)
• Fix for descriptor_pb.rb: google/protobuf should be required first (#9121)

C#

• Correctly set ExtensionRegistry when parsing with MessageParser, but using an already existing CodedInputStream (#7246)
• [C#] Make FieldDescriptor propertyName public (#7642)

Java

• Update changelog to reflect that we are not yet dropping Java 7 support after all

C++

• Make proto2::Message::DiscardUnknownFields() non-virtual
• Separate RepeatedPtrField into its own header file
• For default floating point values of 0, consider all bits significant
• cmake: support MSVC_RUNTIME_LIBRARY property (#8851)
• Fix shadowing warnings (#8926)
• Fix for issue #8484, constant initialization doesn't compile in msvc clang-cl environment (#8993)
• Fix build on AIX and SunOS (#8373) (#9065)
• Add Android stlport and default toolchains to BUILD. (#8290)

Java

• This release drops support for Java 7. Use 3.18.x if you still need Java 7 support.
• For default floating point values of 0, consider all bits significant
• Annotate //java/com/google/protobuf/util/... with nullness annotations
• Use ArrayList copy constructor (#7853)

Kotlin

• Switch Kotlin proto DSLs to be implemented with inline value classes

Python

• Proto2 DecodeError now includes message name in error message
• Make MessageToDict convert map keys to strings (#8122)
• Add python-requires in setup.py (#8989)
• Add python 3.10 (#9034)

JavaScript

• Skip exports if not available by CommonJS (#8856)
• JS: Comply with CSP no-unsafe-eval. (#8864)

PHP

• Added "object" as a reserved name for PHP (#8962)

Ruby

• Override Map.clone to use Map's dup method (#7938)
• Ruby: build extensions for arm64-darwin (#8232)
• Add class method Timestamp.from_time to ruby well known types (#8562)
• Adopt pure ruby DSL implementation for JRuby (#9047)
• Add size to Map class (#8068)

C#

• Correctly set ExtensionRegistry when parsing with MessageParser, but using an already existing CodedInputStream (#7246)
• [C#] Make FieldDescriptor propertyName public (#7642)

C++

• Reduce memory consumption of MessageSet parsing
• This release addresses a Security Advisory for C++ and Python users

Python

• Update setup.py to reflect that we now require at least Python 3.5 (#8989)
• Performance fix for DynamicMessage: force GetRaw() to be inlined (#9023)

Ruby

• Update ruby_generator.cc to allow proto2 imports in proto3 (#9003)

C++

• Fix warnings raised by clang 11 (#8664)
• Make StringPiece constructible from std::string_view (#8707)
• Add missing capability attributes for LLVM 12 (#8714)
• Stop using std::iterator (deprecated in C++17). (#8741)
• Move field_access_listener from libprotobuf-lite to libprotobuf (#8775)
• Fix #7047 Safely handle setlocale (#8735)
• Remove deprecated version of SetTotalBytesLimit() (#8794)
• Support arena allocation of google::protobuf::AnyMetadata (#8758)
• Fix undefined symbol error around SharedCtor() (#8827)
• Fix default value of enum(int) in json_util with proto2 (#8835)
• Better Smaller ByteSizeLong
• Introduce event filters for inject_field_listener_events
• Reduce memory usage of DescriptorPool
• For lazy fields copy serialized form when allowed.
• Re-introduce the InlinedStringField class
• v2 access listener
• Reduce padding in the proto's ExtensionRegistry map.
• GetExtension performance optimizations
• Make tracker a static variable rather than call static functions
• Support extensions in field access listener
• Annotate MergeFrom for field access listener
• Fix incomplete types for field access listener
• Add map_entry/new_map_entry to SpecificField in MessageDifferencer. They record the map items which are different in MessageDifferencer's reporter.
• Reduce binary size due to fieldless proto messages
• TextFormat: ParseInfoTree supports getting field end location in addition to start.
• Fix repeated enum extension size in field listener
• Enable Any Text Expansion for Descriptors::DebugString()
• Switch from int{8,16,32,64} to int{8,16,32,64}_t

Java

• Fix errorprone conflict (#8723)
• Removing deprecated TimeUtil class. (#8749)
• Optimized FieldDescriptor.valueOf() to avoid array copying.
• Removing deprecated TimeUtil class.
• Add Durations.parseUnchecked(String) and Timestamps.parseUnchecked(String)
• FieldMaskUtil: Add convenience method to mask the fields out of a given proto.

JavaScript

• Optimize binary parsing of repeated float64
• Fix for optimization when reading doubles from binary wire format
• Replace toArray implementation with toJSON.

PHP

• Migrate PHP & Ruby to ABSL wyhash (#8854)
• Added support for PHP 8.1 (currently in RC1) to the C extension (#8964)
• Fixed PHP SEGV when constructing messages from a destructor. (#8969)

Ruby

• Move DSL implementation from C to pure Ruby (#8850)
• Fixed a memory bug with RepeatedField#+. (#8970)

Python

• Drops support for 2.7 and 3.5.

Other

• [csharp] ByteString.CreateCodedInput should use ArraySegment offset and count (#8740)
• [ObjC] Add support for using the proto package to prefix symbols. (#8760)
• field_presence.md: fix Go example (#8788)

C++

• Fix warnings raised by clang 11 (#8664)
• Make StringPiece constructible from std::string_view (#8707)
• Add missing capability attributes for LLVM 12 (#8714)
• Stop using std::iterator (deprecated in C++17). (#8741)
• Move field_access_listener from libprotobuf-lite to libprotobuf (#8775)
• Fix #7047 Safely handle setlocale (#8735)
• Remove deprecated version of SetTotalBytesLimit() (#8794)
• Support arena allocation of google::protobuf::AnyMetadata (#8758)
• Fix undefined symbol error around SharedCtor() (#8827)
• Fix default value of enum(int) in json_util with proto2 (#8835)
• Better Smaller ByteSizeLong
• Introduce event filters for inject_field_listener_events
• Reduce memory usage of DescriptorPool
• For lazy fields copy serialized form when allowed.
• Re-introduce the InlinedStringField class
• v2 access listener
• Reduce padding in the proto's ExtensionRegistry map.
• GetExtension performance optimizations
• Make tracker a static variable rather than call static functions
• Support extensions in field access listener
• Annotate MergeFrom for field access listener
• Fix incomplete types for field access listener
• Add map_entry/new_map_entry to SpecificField in MessageDifferencer. They record the map items which are different in MessageDifferencer's reporter.
• Reduce binary size due to fieldless proto messages
• TextFormat: ParseInfoTree supports getting field end location in addition to start.
• Fix repeated enum extension size in field listener
• Enable Any Text Expansion for Descriptors::DebugString()
• Switch from int{8,16,32,64} to int{8,16,32,64}_t

Java

• Fix errorprone conflict (#8723)
• Removing deprecated TimeUtil class. (#8749)
• Optimized FieldDescriptor.valueOf() to avoid array copying.
• Removing deprecated TimeUtil class.
• Add Durations.parseUnchecked(String) and Timestamps.parseUnchecked(String)
• FieldMaskUtil: Add convenience method to mask the fields out of a given proto.

JavaScript

• Optimize binary parsing of repeated float64
• Fix for optimization when reading doubles from binary wire format
• Replace toArray implementation with toJSON.

PHP

• Migrate PHP & Ruby to ABSL wyhash (#8854)

Ruby

• Move DSL implementation from C to pure Ruby (#8850)

Python

• Drops support for 2.7 and 3.5.

Other

• [csharp] ByteString.CreateCodedInput should use ArraySegment offset and count (#8740)
• [ObjC] Add support for using the proto package to prefix symbols. (#8760)
• field_presence.md: fix Go example (#8788)

C++

• Fix warnings raised by clang 11 (#8664)
• Make StringPiece constructible from std::string_view (#8707)
• Add missing capability attributes for LLVM 12 (#8714)
• Stop using std::iterator (deprecated in C++17). (#8741)
• Move field_access_listener from libprotobuf-lite to libprotobuf (#8775)
• Fix #7047 Safely handle setlocale (#8735)
• Remove deprecated version of SetTotalBytesLimit() (#8794)
• Support arena allocation of google::protobuf::AnyMetadata (#8758)
• Fix undefined symbol error around SharedCtor() (#8827)
• Fix default value of enum(int) in json_util with proto2 (#8835)
• Better Smaller ByteSizeLong
• Introduce event filters for inject_field_listener_events
• Reduce memory usage of DescriptorPool
• For lazy fields copy serialized form when allowed.
• Re-introduce the InlinedStringField class
• v2 access listener
• Reduce padding in the proto's ExtensionRegistry map.
• GetExtension performance optimizations
• Make tracker a static variable rather than call static functions
• Support extensions in field access listener
• Annotate MergeFrom for field access listener
• Fix incomplete types for field access listener
• Add map_entry/new_map_entry to SpecificField in MessageDifferencer. They record the map items which are different in MessageDifferencer's reporter.
• Reduce binary size due to fieldless proto messages
• TextFormat: ParseInfoTree supports getting field end location in addition to start.
• Fix repeated enum extension size in field listener
• Enable Any Text Expansion for Descriptors::DebugString()
• Switch from int{8,16,32,64} to int{8,16,32,64}_t

Java

• Fix errorprone conflict (#8723)
• Removing deprecated TimeUtil class. (#8749)
• Optimized FieldDescriptor.valueOf() to avoid array copying.
• Removing deprecated TimeUtil class.
• Add Durations.parseUnchecked(String) and Timestamps.parseUnchecked(String)
• FieldMaskUtil: Add convenience method to mask the fields out of a given proto.

JavaScript

• Optimize binary parsing of repeated float64
• Fix for optimization when reading doubles from binary wire format
• Replace toArray implementation with toJSON.

PHP

• Migrate PHP & Ruby to ABSL wyhash (#8854)

Ruby

• Move DSL implementation from C to pure Ruby (#8850)

Other

• [csharp] ByteString.CreateCodedInput should use ArraySegment offset and count (#8740)
• [ObjC] Add support for using the proto package to prefix symbols. (#8760)
• field_presence.md: fix Go example (#8788)

Python

• Note: This is the last release to support Python 2.7. Future releases will require Python >= 3.5.

C++

• Introduce FieldAccessListener.
• Stop emitting boilerplate {Copy/Merge}From in each ProtoBuf class
• Fixed some uninitialized variable warnings in generated_message_reflection.cc.

Kotlin

• Fix duplicate proto files error (#8699)

Java

• Fixed parser to check that we are at a proper limit when a sub-message has finished parsing.

General

• Support M1 (#8557)

Kotlin

• Fix duplicate class error (#8653)

PHP

• Fixed SEGV in sub-message getters for well-known types when message is unset (#8670)

PHP

• Fixed PHP memory leaks and arginfo errors. (#8614)
• Fixed JSON parser to allow multiple values from the same oneof as long as all but one are null.

Ruby

• Fixed memory bug: properly root repeated/map field when assigning. (#8639)
• Fixed JSON parser to allow multiple values from the same oneof as long as all but one are null.

Protocol Compiler

• Fix the generated source information for reserved values in Enums.

C++

• Fix -Wunused-parameter in map<string, int> fields (fixes #8494) (#8500)
• Use byteswap.h when building against musl libc (#8503)
• Fix -Wundefined-inline error when using SharedCtor() or SharedDtor() (#8532)
• Fix bug where Descriptor::DebugString() printed proto3 synthetic oneofs.
• Provide stable versions of SortAndUnique().
• Make sure to cache proto3 optional message fields when they are cleared.
• Expose UnsafeArena methods to Reflection.
• Use std::string::empty() rather than std::string::size() > 0.

Kotlin

• Introduce support for Kotlin protos (#8272)
• Restrict extension setter and getter operators to non-nullable T.

Java

• updating GSON and Guava to more recent versions (#8524)
• Reduce the time spent evaluating isExtensionNumber by storing the extension ranges in a TreeMap for faster queries. This is particularly relevant for protos which define a large number of extension ranges, for example when each tag is defined as an extension.
• Fix java bytecode estimation logic for optional fields.
• Optimize Descriptor.isExtensionNumber.

Python

• Add MethodDescriptor.CopyToProto() (#8327)
• Remove unused python_protobuf.{cc,h} (#8513)
• Start publishing python aarch64 manylinux wheels normally (#8530)
• Fix constness issue detected by MSVC standard conforming mode (#8568)
• Make JSON parsing match C++ and Java when multiple fields from the same oneof are present and all but one is null.

Ruby

• Add support for proto3 json_name in compiler and field definitions (#8356)
• Fixed memory leak of Ruby arena objects. (#8461)
• Fix source gem compilation (#8471)
• Fix various exceptions in Ruby on 64-bit Windows (#8563)
• Fix crash when calculating Message hash values on 64-bit Windows (#8565)

Conformance Tests

• Added a conformance test for the case of multiple fields from the same oneof.

Other

• Use a newer version of rules_proto, with the new rule proto_descriptor_set (#8469)

Protocol Compiler

• Fix the generated source information for reserved values in Enums.

C++

• Fix -Wunused-parameter in map<string, int> fields (fixes #8494) (#8500)
• Use byteswap.h when building against musl libc (#8503)
• Fix -Wundefined-inline error when using SharedCtor() or SharedDtor() (#8532)
• Fix bug where Descriptor::DebugString() printed proto3 synthetic oneofs.
• Provide stable versions of SortAndUnique().
• Make sure to cache proto3 optional message fields when they are cleared.
• Expose UnsafeArena methods to Reflection.
• Use std::string::empty() rather than std::string::size() > 0.

Kotlin

• Restrict extension setter and getter operators to non-nullable T.

Java

• updating GSON and Guava to more recent versions (#8524)
• Reduce the time spent evaluating isExtensionNumber by storing the extension ranges in a TreeMap for faster queries. This is particularly relevant for protos which define a large number of extension ranges, for example when each tag is defined as an extension.
• Fix java bytecode estimation logic for optional fields.
• Optimize Descriptor.isExtensionNumber.

Python

• [python-runtime] Add MethodDescriptor.CopyToProto() (#8327)
• Remove unused python_protobuf.{cc,h} (#8513)
• Start publishing python aarch64 manylinux wheels normally (#8530)
• Fix constness issue detected by MSVC standard conforming mode (#8568)
• Make JSON parsing match C++ and Java when multiple fields from the same oneof are present and all but one is null.

Ruby

• Ruby: Add support for proto3 json_name in compiler and field definitions (#8356)
• Fixed memory leak of Ruby arena objects. (#8461)
• Fix source gem compilation (#8471)
• fix(ruby): Fix various exceptions in Ruby on 64-bit Windows (#8563)
• fix(ruby): Fix crash when calculating Message hash values on 64-bit Windows (#8565)

Conformance Tests

• Added a conformance test for the case of multiple fields from the same oneof.

Other

• Opensourcing kotlin protos (#8272)
• Use a newer version of rules_proto, with the new rule proto_descriptor_set (#8469)

C++

• Fix compiler warnings issue found in conformance_test_runner #8189 (#8190)
• Fix MinGW-w64 build issues. (#8286)
• [Protoc] C++ Resolved an issue where NO_DESTROY and CONSTINIT are in incorrect order (#8296)
• Fix PROTOBUF_CONSTINIT macro redefinition (#8323)
• Delete StringPiecePod (#8353)
• Fix gcc error: comparison of unsigned expression in '>= 0' is always … (#8309)
• Fix cmake install on iOS (#8301)
• Create a CMake option to control whether or not RTTI is enabled (#8347)
• Fix endian.h location on FreeBSD (#8351)
• Refactor util::Status (#8354)
• Make util::Status more similar to absl::Status (#8405)
• Fix -Wsuggest-destructor-override for generated C++ proto classes. (#8408)
• Refactor StatusOr and StringPiece (#8406)
• Refactor uint128 (#8416)
• The ::pb namespace is no longer exposed due to conflicts.
• Allow MessageDifferencer::TreatAsSet() (and friends) to override previous calls instead of crashing.
• Reduce the size of generated proto headers for protos with string or bytes fields.
• Move arena() operation on uncommon path to out-of-line routine
• For iterator-pair function parameter types, take both iterators by value.
• Code-space savings and perhaps some modest performance improvements in RepeatedPtrField.
• Eliminate nullptr check from every tag parse.
• Remove unused _$name$cached_byte_size fields.
• Serialize extension ranges together when not broken by a proto field in the middle.
• Do out-of-line allocation and deallocation of string object in ArenaString.
• Streamline ParseContext::ParseMessage<T> to avoid code bloat and improve performance.
• New member functions RepeatedField::Assign, RepeatedPtrField::{Add, Assign}.
• Fix undefined behavior warning due to innocuous uninitialization of value on an error path.
• Avoid expensive inlined code space for encoding message length for messages

  = 128 bytes and instead do a procedure call to a shared out-of-line routine.

• util::DefaultFieldComparator will be final in a future version of protobuf. Subclasses should inherit from SimpleFieldComparator instead.

C#

• Add .NET 5 target and improve WriteString performance with SIMD (#8147)

Java

• deps: update JUnit and Truth (#8319)
• Detect invalid overflow of byteLimit and return InvalidProtocolBufferException as documented.
• Exceptions thrown while reading from an InputStream in parseFrom are now included as causes.
• Support potentially more efficient proto parsing from RopeByteStrings.
• Clarify runtime of ByteString.Output.toStringBuffer().
• Added UnsafeByteOperations to protobuf-lite (#8426)

JavaScript

• Make Any.pack() chainable.

Python

• Fix some constness / char literal issues being found by MSVC standard conforming mode (#8344)
• Switch on "new" buffer API (#8339)
• Enable crosscompiling aarch64 python wheels under dockcross manylinux docker image (#8280)
• Fixed a bug in text format where a trailing colon was printed for repeated field.
• When TextFormat encounters a duplicate message map key, replace the current one instead of merging.

Objective-C

• Move the class map to a CFDictionary. (#8328)

PHP

• read_property() handler is not supposed to return NULL (#8362)
• Changed parameter type from long to integer (#7613)
• fix: README supported PHP version for C extension (#8236)

Ruby

• Fixed quadratic memory usage when appending to arrays. (#8364)
• Fixed memory leak of Ruby arena objects. (#8461)
• Add support for proto3 json_name in compiler and field definitions. (#8356)

Other

• Some doc on AOT compilation and protobuf (#8294)
• [CMake] Ability to pass options to protoc executable from cmake (#8374)
• Add --fatal_warnings flag to treat warnings as errors (#8131)
• [bazel] Remove deprecated way to depend on googletest (#8396)
• add error returns missing from protoc to prevent it from exiting with… (#8409)

Ruby

• Fixed memory leak of Ruby arena objects. (#8462)
• Add support for proto3 json_name in compiler and field definitions. (#8356)

Ruby

• Fixed memory leak of Ruby arena objects (#8461)

C++

• Remove the ::pb namespace (alias) (#8423)

Ruby

• Fix unbounded memory growth for Ruby <2.7 (#8429)
• Fixed message equality in cases where the message type is different (#8434)

Ruby

• Fixed bug in string comparison logic (#8386)

Ruby

• Fixed quadratic memory use in array append (#8379)

PHP

• Fixed quadratic memory use in array append (#8379)

C++

• Do not disable RTTI by default in the CMake build (#8377)

Ruby

• Fixed SEGV when users pass nil messages (#8363)
• Fixed quadratic memory usage when appending to arrays (#8364)

C++

• Create a CMake option to control whether or not RTTI is enabled (#8361)

PHP

• read_property() handler is not supposed to return NULL (#8362)

Ruby

• Ruby <2.7 now uses WeakMap too, which prevents memory leaks. (#8341)

Ruby

• Fix for FieldDescriptor.get(msg) (#8330)

C++

• Fix PROTOBUF_CONSTINIT macro redefinition (#8323)

Ruby

• Bugfix for Message.[] for repeated or map fields (#8313)
• Fix for truncating behavior when converting Float to Duration (#8320)

C++

• Small fixes for MinGW and for C++20 with GCC (#8318)

Protocol Compiler

• Optional fields for proto3 are enabled by default, and no longer require the --experimental_allow_proto3_optional flag.

C++

• MessageDifferencer: fixed bug when using custom ignore with multiple unknown fields
• Use init_seg in MSVC to push initialization to an earlier phase.
• Runtime no longer triggers -Wsign-compare warnings.
• Fixed -Wtautological-constant-out-of-range-compare warning.
• DynamicCastToGenerated works for nullptr input for even if RTTI is disabled
• Arena is refactored and optimized.
• Clarified/specified that the exact value of Arena::SpaceAllocated() is an implementation detail users must not rely on. It should not be used in unit tests.
• Change the signature of Any::PackFrom() to return false on error.
• Add fast reflection getter API for strings.
• Constant initialize the global message instances
• Avoid potential for missed wakeup in UnknownFieldSet
• Now Proto3 Oneof fields have "has" methods for checking their presence in C++.
• Bugfix for NVCC
• Return early in _InternalSerialize for empty maps.
• Adding functionality for outputting map key values in proto path logging output (does not affect comparison logic) and stop printing 'value' in the path. The modified print functionality is in the MessageDifferencer::StreamReporter.
• Fixed https://github.com/protocolbuffers/protobuf/issues/8129
• Ensure that null char symbol, package and file names do not result in a crash.
• Constant initialize the global message instances
• Pretty print 'max' instead of numeric values in reserved ranges.
• Removed remaining instances of std::is_pod, which is deprecated in C++20.
• Changes to reduce code size for unknown field handling by making uncommon cases out of line.
• Fix std::is_pod deprecated in C++20 (#7180)
• Fix some -Wunused-parameter warnings (#8053)
• Fix detecting file as directory on zOS issue #8051 (#8052)
• Don't include sys/param.h for _BYTE_ORDER (#8106)
• remove CMAKE_THREAD_LIBS_INIT from pkgconfig CFLAGS (#8154)
• Fix TextFormatMapTest.DynamicMessage issue#5136 (#8159)
• Fix for compiler warning issue#8145 (#8160)
• fix: support deprecated enums for GCC < 6 (#8164)
• Fix some warning when compiling with Visual Studio 2019 on x64 target (#8125)

Python

• Provided an override for the reverse() method that will reverse the internal collection directly instead of using the other methods of the BaseContainer.
• MessageFactory.CreateProtoype can be overridden to customize class creation.
• Fix PyUnknownFields memory leak (#7928)
• Add macOS big sur compatibility (#8126)

JavaScript

• Generate getDescriptor methods with * as their this type.
• Enforce let/const for generated messages.
• js/binary/utils.js: Fix jspb.utils.joinUnsignedDecimalString to work with negative bitsLow and low but non-zero bitsHigh parameter. (#8170)

PHP

• Added support for PHP 8. (#8105)
• unregister INI entries and fix invalid read on shutdown (#8042)
• Fix PhpDoc comments for message accessors to include "|null". (#8136)
• fix: convert native PHP floats to single precision (#8187)
• Fixed PHP to support field numbers >=2**28. (#8235)
• feat: add support for deprecated fields to PHP compiler (#8223)
• Protect against stack overflow if the user derives from Message. (#8248)
• Fixed clone for Message, RepeatedField, and MapField. (#8245)
• Updated upb to allow nonzero offset minutes in JSON timestamps. (#8258)

Ruby

• Added support for Ruby 3. (#8184)
• Rewrote the data storage layer to be based on upb_msg objects from the upb library. This should lead to much better parsing performance, particularly for large messages. (#8184).
• Fill out JRuby support (#7923)
• [Ruby] Fix: (SIGSEGV) gRPC-Ruby issue on Windows. memory alloc infinite recursion/run out of memory (#8195)
• Fix jruby support to handle messages nested more than 1 level deep (#8194)

Java

• Avoid possible UnsupportedOperationException when using CodedInputSteam with a direct ByteBuffer.
• Make Durations.comparator() and Timestamps.comparator() Serializable.
• Add more detailed error information for dynamic message field type validation failure
• Removed declarations of functions declared in java_names.h from java_helpers.h.
• Now Proto3 Oneof fields have "has" methods for checking their presence in Java.
• Annotates Java proto generated *_FIELD_NUMBER constants.
• Add -assumevalues to remove JvmMemoryAccessor on Android.

C#

• Fix parsing negative Int32Value that crosses segment boundary (#8035)
• Change ByteString to use memory and support unsafe create without copy (#7645)
• Optimize MapField serialization by removing MessageAdapter (#8143)
• Allow FileDescriptors to be parsed with extension registries (#8220)
• Optimize writing small strings (#8149)

Protocol Compiler

• The proto compiler no longer requires a .proto filename when it is not generating code.
• Added flag --deterministic_output to protoc --encode=....
• Fixed deadlock when using google.protobuf.Any embedded in aggregate options.

C++

• Arenas are now unconditionally enabled. cc_enable_arenas no longer has any effect.
• Removed inlined string support, which is incompatible with arenas.
• Fix a memory corruption bug in reflection when mixing optional and non-optional fields.
• Make SpaceUsed() calculation more thorough for map fields.
• Add stack overflow protection for text format with unknown field values.
• FieldPath::FollowAll() now returns a bool to signal if an out-of-bounds error was encountered.
• Performance improvements for Map.
• Minor formatting fix when dumping a descriptor to .proto format with DebugString.
• UBSAN fix in RepeatedField (#2073).
• When running under ASAN, skip a test that makes huge allocations.
• Fixed a crash that could happen when creating more than 256 extensions in a single message.
• Fix a crash in BuildFile when passing in invalid descriptor proto.
• Parser security fix when operating with CodedInputStream.
• Warn against the use of AllowUnknownExtension.
• Migrated to C++11 for-range loops instead of index-based loops where possible. This fixes a lot of warnings when compiling with -Wsign-compare.
• Fix segment fault for proto3 optional (#7805)
• Adds a CMake option to build libprotoc separately (#7949)

Java

• Bugfix in mergeFrom() when a oneof has multiple message fields.
• Fix RopeByteString.RopeInputStream.read() returning -1 when told to read 0 bytes when not at EOF.
• Redefine remove(Object) on primitive repeated field Lists to avoid autoboxing.
• Support "\u" escapes in textformat string literals.
• Trailing empty spaces are no longer ignored for FieldMask.
• Fix FieldMaskUtil.subtract to recursively remove mask.
• Mark enums with @java.lang.Deprecated if the proto enum has option deprecated = true;.
• Adding forgotten duration.proto to the lite library (#7738)

Python

• Print google.protobuf.NullValue as null instead of "NULL_VALUE" when it is used outside WKT Value/Struct.
• Fix bug occurring when attempting to deep copy an enum type in python 3.
• Add a setuptools extension for generating Python protobufs (#7783)
• Remove uses of pkg_resources in non-namespace packages. (#7902)
• [bazel/py] Omit google/init.py from the Protobuf runtime. (#7908)
• Removed the unnecessary setuptools package dependency for Python package (#7511)
• Fix PyUnknownFields memory leak (#7928)

PHP

• Added support for "==" to the PHP C extension (#7883)
• Added == operators for Map and Array. (#7900)
• Native C well-known types (#7944)
• Optimized away hex2bin() call in generated code (#8006)
• New version of upb, and a new hash function wyhash in third_party. (#8000)
• add missing hasOneof method to check presence of oneof fields (#8003)

Go

• Update go_package options to reference google.golang.org/protobuf module.

C#

• annotate ByteString.CopyFrom(ReadOnlySpan<byte>) as SecuritySafeCritical (#7701)
• Fix C# optional field reflection when there are regular fields too (#7705)
• Fix parsing negative Int32Value that crosses segment boundary (#8035)

Javascript

• JS: parse (un)packed fields conditionally (#7379)

PHP

• The C extension is completely rewritten. The new C extension has significantly better parsing performance and fixes a handful of conformance issues. It will also make it easier to add support for more features like proto2 and proto3 presence.
• The new C extension does not support PHP 5.x, which is the reason for the major version bump. PHP 5.x users can still use pure-PHP.

C++

• Removed deprecated unsafe arena string accessors
• Enabled heterogeneous lookup for std::string keys in maps.
• Removed implicit conversion from StringPiece to std::string
• Fix use-after-destroy bug when the Map is allocated in the arena.
• Improved the randomness of map ordering
• Added stack overflow protection for text format with unknown fields
• Use std::hash for proto maps to help with portability.
• Added more Windows macros to proto whitelist.
• Arena constructors for map entry messages are now marked "explicit" (for regular messages they were already explicit).
• Fix subtle aliasing bug in RepeatedField::Add
• Fix mismatch between MapEntry ByteSize and Serialize with respect to unset fields.

Python

• JSON format conformance fixes:
  • Reject lowercase t for Timestamp json format.
  • Print full_name directly for extensions (no camelCase).
  • Reject boolean values for integer fields.
  • Reject NaN, Infinity, -Infinity that is not quoted.
  • Base64 fixes for bytes fields: accept URL-safe base64 and missing padding.
• Bugfix for fields/files named "async" or "await".
• Improved the error message when AttributeError is returned from getattr in EnumTypeWrapper.

Java

• Fixed a bug where setting optional proto3 enums with setFooValue() would not mark the value as present.
• Add Subtract function to FieldMaskUtil.

C#

• Dropped support for netstandard1.0 (replaced by support for netstandard1.1). This was required to modernize the parsing stack to use the Span<byte> type internally. (#7351)
• Add ParseFrom(ReadOnlySequence<byte>) method to enable GC friendly parsing with reduced allocations and buffer copies. (#7351)
• Add support for serialization directly to a IBufferWriter<byte> or to a Span<byte> to enable GC friendly serialization. The new API is available as extension methods on the IMessage type. (#7576)
• Add GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE define to make generated code compatible with old C# compilers (pre-roslyn compilers from .NET framework and old versions of mono) that do not support ref structs. Users that are still on a legacy stack that does not support C# 7.2 compiler might need to use the new define in their projects to be able to build the newly generated code. (#7490)
• Due to the major overhaul of parsing and serialization internals (#7351 and #7576), it is recommended to regenerate your generated code to achieve the best performance (the legacy generated code will still work, but might incur a slight performance penalty).

C++

• Simplified the template export macros to fix the build for mingw32. (#7539)

Objective-C

• Fix for the :protobuf_objc target in the Bazel BUILD file. (#7538)

Ruby

• Re-add binary gems for Ruby 2.3 and 2.4. These are EOL upstream, however many people still use them and dropping support will require more coordination. (#7529, #7531).

Protocol Compiler

• [experimental] Singular, non-message typed fields in proto3 now support presence tracking. This is enabled by adding the "optional" field label and passing the --experimental_allow_proto3_optional flag to protoc.
  • For usage info, see docs/field_presence.md.
  • During this experimental phase, code generators should update to support proto3 presence, see docs/implementing_proto3_presence.md for instructions.
• Allow duplicate symbol names when multiple descriptor sets are passed on the command-line, to match the behavior when multiple .proto files are passed.
• Deterministic protoc --descriptor_set_out (#7175)

C++

• [experimental] Added proto3 presence support.
• New descriptor APIs to support proto3 presence.
• Fix for #7463 in -rc1 (core dump mixing optional and singular fields in proto3)
• Enable Arenas by default on all .proto files.
• Documented that users are not allowed to subclass Message or MessageLite.
• Mark generated classes as final; inheriting from protos is strongly discouraged.
• Add stack overflow protection for text format with unknown fields.
• Add accessors for map key and value FieldDescriptors.
• Add FieldMaskUtil::FromFieldNumbers().
• MessageDifferencer: use ParsePartial() on Any fields so the diff does not fail when there are missing required fields.
• ReflectionOps::Merge(): lookup messages in the right factory, if it can.
• Added Descriptor::WellKnownTypes enum and Descriptor::well_known_type() accessor as an easier way of determining if a message is a Well-Known Type.
• Optimized RepeatedField::Add() when it is used in a loop.
• Made proto move/swap more efficient.
• De-virtualize the GetArena() method in MessageLite.
• Improves performance of json_stream_parser.cc by factor 1000 (#7230)
• bug: #7076 undefine Windows OUT and OPTIONAL macros (#7087)
• Fixed a bug in FieldDescriptor::DebugString() that would erroneously print an "optional" label for a field in a oneof.
• Fix bug in parsing bool extensions that assumed they are always 1 byte.
• Fix off-by-one error in FieldOptions::ByteSize() when extensions are present.
• Clarified the comments to show an example of the difference between Descriptor::extension and DescriptorPool::FindAllExtensions.
• Add a compiler option 'code_size' to force optimize_for=code_size on all protos where this is possible.

Java

• [experimental] Added proto3 presence support.
• Fix for #7480 in -rc1 ("TextFormat and JsonFormat ignore experimental proto3 optional enums")
• Fix for #7505 in -rc1 (" toString() returns incorrect ascii when there are duplicate keys in a map")
• Mark java enum _VALUE constants as @Deprecated if the enum field is deprecated
• reduce <clinit> size for enums with allow_alias set to true.
• Sort map fields alphabetically by the field's key when printing textproto.
• TextFormat.merge() handles Any as top level type.
• Throw a descriptive IllegalArgumentException when calling getValueDescriptor() on enum special value UNRECOGNIZED instead of ArrayIndexOutOfBoundsException.
• Fixed an issue with JsonFormat.printer() where setting printingEnumsAsInts() would override the configuration passed into includingDefaultValueFields().
• Implement overrides of indexOf() and contains() on primitive lists returned for repeated fields to avoid autoboxing the list contents.
• Add overload to FieldMaskUtil.fromStringList that accepts a descriptor.
• [bazel] Move Java runtime/toolchains into //java (#7190)

Python

• [experimental] Added proto3 presence support.
• [experimental] fast import protobuf module, only works with cpp generated code linked in.
• Truncate 'float' fields to 4 bytes of precision in setters for pure-Python implementation (C++ extension was already doing this).
• Fixed a memory leak in C++ bindings.
• Added a deprecation warning when code tries to create Descriptor objects directly.
• Fix unintended comparison between bytes and string in descriptor.py.
• Avoid printing excess digits for float fields in TextFormat.
• Remove Python 2.5 syntax compatibility from the proto compiler generated _pb2.py module code.
• Drop 3.3, 3.4 and use single version docker images for all python tests (#7396)

JavaScript

• Fix js message pivot selection (#6813)

PHP

• Persistent Descriptor Pool (#6899)
• Implement lazy loading of php class for proto messages (#6911)
• Correct @return in Any.unpack docblock (#7089)
• Ignore unknown enum value when ignore_unknown specified (#7455)

Ruby

• [experimental] Implemented proto3 presence for Ruby. (#7406)
• Stop building binary gems for ruby <2.5 (#7453)
• Fix for wrappers with a zero value (#7195)
• Fix for JSON serialization of 0/empty-valued wrapper types (#7198)
• Call "Class#new" over rb_class_new_instance in decoding (#7352)
• Build extensions for Ruby 2.7 (#7027)
• assigning 'nil' to submessage should clear the field. (#7397)

C#

• [experimental] Add support for proto3 presence fields in C# (#7382)
• Cleanup various bits of Google.Protobuf (#6674)
• Fix conformance test failures for Google.Protobuf (#6910)
• Fix latest ArgumentException for C# extensions (#6938)
• Remove unnecessary branch from ReadTag (#7289)
• Enforce recursion depth checking for unknown fields (#7132)
• Mark GetOption API as obsolete and expose the "GetOptions()" method on descriptors instead (#7491)
• Remove Has/Clear members for C# message fields in proto2 (#7429)

Objective-C

• [experimental] ObjC Proto3 optional support (#7421)
• Block subclassing of generated classes (#7124)
• Use references to Obj C classes instead of names in descriptors. (#7026)
• Revisit how the WKTs are bundled with ObjC. (#7173)

Other

• Add a proto_lang_toolchain for javalite (#6882)
• [bazel] Update gtest and deprecate //external:{gtest,gtest_main} (#7237)
• Add application note for explicit presence tracking. (#7390)
• Howto doc for implementing proto3 presence in a code generator. (#7407)

C++ / Python

• Fix for #7463 ("mixing with optional fields: core dump --experimental_allow_proto3_optional")

Java

• Fix for #7480 ("TextFormat and JsonFormat ignore experimental proto3 optional enums")

PHP

• Ignore unknown enum value when ignore_unknown specified (#7455)

C#

• Mark GetOption API as obsolete and expose the "GetOptions()" method on descriptors instead (#7491)
• Remove Has/Clear members for C# message fields in proto2 (#7429)

Protocol Compiler

• [experimental] Singular, non-message typed fields in proto3 now support presence tracking. This is enabled by adding the "optional" field label and passing the --experimental_allow_proto3_optional flag to protoc.
  • For usage info, see docs/field_presence.md.
  • During this experimental phase, code generators should update to support proto3 presence, see docs/implementing_proto3_presence.md for instructions.
• Allow duplicate symbol names when multiple descriptor sets are passed on the command-line, to match the behavior when multiple .proto files are passed.
• Deterministic protoc --descriptor_set_out (#7175)

C++

• [experimental] Added proto3 presence support.
• New descriptor APIs to support proto3 presence.
• Enable Arenas by default on all .proto files.
• Documented that users are not allowed to subclass Message or MessageLite.
• Mark generated classes as final; inheriting from protos is strongly discouraged.
• Add stack overflow protection for text format with unknown fields.
• Add accessors for map key and value FieldDescriptors.
• Add FieldMaskUtil::FromFieldNumbers().
• MessageDifferencer: use ParsePartial() on Any fields so the diff does not fail when there are missing required fields.
• ReflectionOps::Merge(): lookup messages in the right factory, if it can.
• Added Descriptor::WellKnownTypes enum and Descriptor::well_known_type() accessor as an easier way of determining if a message is a Well-Known Type.
• Optimized RepeatedField::Add() when it is used in a loop.
• Made proto move/swap more efficient.
• De-virtualize the GetArena() method in MessageLite.
• Improves performance of json_stream_parser.cc by factor 1000 (#7230)
• bug: #7076 undefine Windows OUT and OPTIONAL macros (#7087)
• Fixed a bug in FieldDescriptor::DebugString() that would erroneously print an "optional" label for a field in a oneof.
• Fix bug in parsing bool extensions that assumed they are always 1 byte.
• Fix off-by-one error in FieldOptions::ByteSize() when extensions are present.
• Clarified the comments to show an example of the difference between Descriptor::extension and DescriptorPool::FindAllExtensions.
• Add a compiler option 'code_size' to force optimize_for=code_size on all protos where this is possible.

Java

• [experimental] Added proto3 presence support.
• Mark java enum _VALUE constants as @Deprecated if the enum field is deprecated
• reduce <clinit> size for enums with allow_alias set to true.
• Sort map fields alphabetically by the field's key when printing textproto.
• TextFormat.merge() handles Any as top level type.
• Throw a descriptive IllegalArgumentException when calling getValueDescriptor() on enum special value UNRECOGNIZED instead of ArrayIndexOutOfBoundsException.
• Fixed an issue with JsonFormat.printer() where setting printingEnumsAsInts() would override the configuration passed into includingDefaultValueFields().
• Implement overrides of indexOf() and contains() on primitive lists returned for repeated fields to avoid autoboxing the list contents.
• Add overload to FieldMaskUtil.fromStringList that accepts a descriptor.
• [bazel] Move Java runtime/toolchains into //java (#7190)

Python

• [experimental] Added proto3 presence support.
• [experimental] fast import protobuf module, only works with cpp generated code linked in.
• Truncate 'float' fields to 4 bytes of precision in setters for pure-Python implementation (C++ extension was already doing this).
• Fixed a memory leak in C++ bindings.
• Added a deprecation warning when code tries to create Descriptor objects directly.
• Fix unintended comparison between bytes and string in descriptor.py.
• Avoid printing excess digits for float fields in TextFormat.
• Remove Python 2.5 syntax compatibility from the proto compiler generated _pb2.py module code.
• Drop 3.3, 3.4 and use single version docker images for all python tests (#7396)

JavaScript

• Fix js message pivot selection (#6813)

PHP

• Persistent Descriptor Pool (#6899)
• Implement lazy loading of php class for proto messages (#6911)
• Correct @return in Any.unpack docblock (#7089)

Ruby

• [experimental] Implemented proto3 presence for Ruby. (#7406)
• Stop building binary gems for ruby <2.5 (#7453)
• Fix for wrappers with a zero value (#7195)
• Fix for JSON serialization of 0/empty-valued wrapper types (#7198)
• Call "Class#new" over rb_class_new_instance in decoding (#7352)
• Build extensions for Ruby 2.7 (#7027)
• assigning 'nil' to submessage should clear the field. (#7397)

C#

• [experimental] Add support for proto3 presence fields in C# (#7382)
• Cleanup various bits of Google.Protobuf (#6674)
• Fix conformance test failures for Google.Protobuf (#6910)
• Fix latest ArgumentException for C# extensions (#6938)
• Remove unnecessary branch from ReadTag (#7289)
• Enforce recursion depth checking for unknown fields (#7132)

Objective-C

• [experimental] ObjC Proto3 optional support (#7421)
• Block subclassing of generated classes (#7124)
• Use references to Obj C classes instead of names in descriptors. (#7026)
• Revisit how the WKTs are bundled with ObjC. (#7173)

Other

• Add a proto_lang_toolchain for javalite (#6882)
• [bazel] Update gtest and deprecate //external:{gtest,gtest_main} (#7237)
• Add application note for explicit presence tracking. (#7390)
• Howto doc for implementing proto3 presence in a code generator. (#7407)

C++

• Add OUT and OPTIONAL to windows portability files (#7087)

PHP

• Refactored ulong to zend_ulong for php7.4 compatibility (#7147)
• Call register_class before getClass from desc to fix segfault (#7077)

PHP

• Make c extension portable for php 7.4 (#6968)

PHP

• Extern declare protobuf_globals (#6946)

C++

• Make serialization method naming consistent
• Make proto runtime + generated code free of deprecation warnings
• Moved ShutdownProtobufLibrary() to message_lite.h. For backward compatibility a declaration is still available in stubs/common.h, but users should prefer message_lite.h
• Removed non-namespace macro EXPECT_OK()
• Removed mathlimits.h from stubs in favor of using std::numeric_limits from C++11
• Fixed bug in parser when ending on a group tag
• Add a helper function to UnknownFieldSet to deal with the changing return value of message::unknown_fields()
• Fix incorrect use of string_view iterators
• Support direct pickling of nested messages
• Skip extension tag validation for MessageSet if unknown dependencies are allowed
• Updated deprecation macros to annotate deprecated code (#6612)
• Remove conversion warning in MapEntryFuncs::ByteSizeLong (#6766)
• Revert "Make shared libraries be able to link to MSVC static runtime libraries, so that VC runtime is not required." (#6914)

Java

• Remove the usage of MethodHandle, so that Android users prior to API version 26 can use protobuf-java
• Publish ProGuard config for javalite
• Fix for StrictMode disk read violation in ExtensionRegistryLite
• Include part of the ByteString's content in its toString().
• Include unknown fields when merging proto3 messages in Java lite builders

Python

• Add float_precision option in json format printer
• Optionally print bytes fields as messages in unknown fields, if possible
• FieldPath: fix testing IsSet on root path ''
• Experimental code gen (fast import protobuf module) which only work with cpp generated code linked in

JavaScript

• Remove guard for Symbol iterator for jspb.Map

PHP

• Avoid too much overhead in layout_init (#6716)
• Lazily Create Singular Wrapper Message (#6833)
• Implement lazy loading of php class for proto messages (#6911)

Ruby

• Ruby lazy wrappers optimization (#6797)

C#

• (RepeatedField): Capacity property to resize the internal array (#6530)
• Experimental proto2 support is now officially available (#4642, #5183, #5350, #5936)
• Getting started doc: https://github.com/protocolbuffers/protobuf/blob/master/docs/csharp/proto2.md
• Add length checks to ExtensionCollection (#6759)
• Optimize parsing of some primitive and wrapper types (#6843)
• Use 3 parameter Encoding.GetString for default string values (#6828)
• Change _Extensions property to normal body rather than expression (#6856)

Objective C

• Fixed unaligned reads for 32bit arm with newer Xcode versions (#6678)

PHP

• Implement lazy loading of php class for proto messages (#6911)
• Fixes https://github.com/protocolbuffers/protobuf/issues/6918

C++

• Make serialization method naming consistent
• Make proto runtime + generated code free of deprecation warnings
• Moved ShutdownProtobufLibrary() to message_lite.h. For backward compatibility a declaration is still available in stubs/common.h, but users should prefer message_lite.h
• Removed non-namespace macro EXPECT_OK()
• Removed mathlimits.h from stubs in favor of using std::numeric_limits from C++11
• Fixed bug in parser when ending on a group tag
• Add a helper function to UnknownFieldSet to deal with the changing return value of message::unknown_fields()
• Fix incorrect use of string_view iterators
• Support direct pickling of nested messages
• Skip extension tag validation for MessageSet if unknown dependencies are allowed
• Updated deprecation macros to annotate deprecated code (#6612)
• Remove conversion warning in MapEntryFuncs::ByteSizeLong (#6766)

Java

• Remove the usage of MethodHandle, so that Android users prior to API version 26 can use protobuf-java
• Publish ProGuard config for javalite
• Fix for StrictMode disk read violation in ExtensionRegistryLite
• Include part of the ByteString's content in its toString().
• Include unknown fields when merging proto3 messages in Java lite builders

Python

• Add float_precision option in json format printer
• Optionally print bytes fields as messages in unknown fields, if possible
• FieldPath: fix testing IsSet on root path ''
• Experimental code gen (fast import protobuf module) which only work with cpp generated code linked in

JavaScript

• Remove guard for Symbol iterator for jspb.Map

PHP

• Avoid too much overhead in layout_init (#6716)
• Lazily Create Singular Wrapper Message (#6833)

Ruby

• Ruby lazy wrappers optimization (#6797)

C#

• (RepeatedField): Capacity property to resize the internal array (#6530)
• Experimental proto2 support is now officially available (#4642, #5183, #5350, #5936)
• Getting started doc: https://github.com/protocolbuffers/protobuf/blob/master/docs/csharp/proto2.md
• Add length checks to ExtensionCollection (#6759)
• Optimize parsing of some primitive and wrapper types (#6843)
• Use 3 parameter Encoding.GetString for default string values (#6828)
• Change _Extensions property to normal body rather than expression (#6856)

Objective C

• Fixed unaligned reads for 32bit arm with newer Xcode versions (#6678)

C++

• Switch the proto parser to the faster MOMI parser.
• Properly escape Struct keys in the proto3 JSON serializer.
• Fix crash on uninitialized map entries.
• Informed the compiler of has-bit invariant to produce better code
• Unused imports of files defining descriptor extensions will now be reported
• Add proto2::util::RemoveSubranges to remove multiple subranges in linear time.
• Added BaseTextGenerator::GetCurrentIndentationSize()
• Made implicit weak fields compatible with the Apple linker
• Support 32 bit values for ProtoStreamObjectWriter to Struct.
• Removed the internal-only header coded_stream_inl.h and the internal-only methods defined there.
• Enforced no SWIG wrapping of descriptor_database.h (other headers already had this restriction).
• Implementation of the equivalent of the MOMI parser for serialization. This removes one of the two serialization routines, by making the fast array serialization routine completely general. SerializeToCodedStream can now be implemented in terms of the much much faster array serialization. The array serialization regresses slightly, but when array serialization is not possible this wins big.
• Do not convert unknown field name to snake case to accurately report error.
• Fix a UBSAN warnings. (#6333)
• Add podspec for C++ (#6404)
• protoc: fix source code info location for missing label (#6436)
• C++ Add move constructor for Reflection's SetString (#6477)

Java

This release has a known issue on Android API level <26 (https://github.com/protocolbuffers/protobuf/issues/6718) if you are using protobuf-java in Android. protobuf-javalite users will be fine.

• Call loadDescriptor outside of synchronized block to remove one possible source of deadlock.
• Have oneof enums implement a separate interface (other than EnumLite) for clarity.
• Opensource Android Memory Accessors
• Update TextFormat to make use of the new TypeRegistry.
• Support getFieldBuilder and getRepeatedFieldBuilder in ExtendableBuilder
• Update JsonFormat to make use of the new TypeRegistry.
• Add proguard config generator for GmmBenchmarkSuiteLite.
• Change ProtobufArrayList to use Object[] instead of ArrayList for 5-10% faster parsing
• Implement ProtobufArrayList.add(E) for 20% (5%-40%) faster overall protolite2 parsing
• Make a copy of JsonFormat.TypeRegistry at the protobuf top level package. This will eventually replace JsonFormat.TypeRegistry.
• Fix javadoc warnings in generated files (#6231)
• Java: Add Automatic-Module-Name entries to the Manifest (#6568)

Python

• Add descriptor methods in descriptor_pool are deprecated.
• Uses explicit imports to prevent multithread test failures in py3.
• Added delitem for Python extension dict
• Update six version to 1.12.0 and fix legacy_create_init issue (#6391)

JavaScript

• Remove deprecated boolean option to getResultBase64String().
• Fix sint64 zig-zag encoding.
• Simplify hash64 string conversion to avoid DIGIT array. Should reduce overhead if these functions aren't used, and be more efficient by avoiding linear array searches.
• Change the parameter types of binaryReaderFn in ExtensionFieldBinaryInfo to (number, ?, ?).
• Create dates.ts and time_of_days.ts to mirror Java versions. This is a near-identical conversion of c.g.type.util.{Dates,TimeOfDays} respectively.
• Migrate moneys to TypeScript.

PHP

• Fix incorrect leap day for Timestamp (#6696)
• Initialize well known type values (#6713)

Ruby

Update 2019-10-04: Ruby release has been rolled back due to https://github.com/grpc/grpc/issues/20471. We will upload a new version once the bug is fixed.

• Fix scope resolution for Google namespace (#5878)
• Support hashes for struct initializers (#5716)
• Optimized away the creation of empty string objects. (#6502)
• Roll forward Ruby upb changes now that protobuf Ruby build is fixed (#5866)
• Optimized layout_mark() for Ruby (#6521)
• Optimization for layout_init() (#6547)
• Fix for GC of Ruby map frames. (#6533)
• Fixed leap year handling by reworking upb_mktime() -> upb_timegm(). (#6695)

Objective C

• Remove OSReadLittle* due to alignment requirements (#6678)
• Don't use unions and instead use memcpy for the type swaps. (#6672)

Other

• Override CocoaPods module to lowercase (#6464)

C++

• Switch the proto parser to the faster MOMI parser.
• Properly escape Struct keys in the proto3 JSON serializer.
• Fix crash on uninitialized map entries.
• Informed the compiler of has-bit invariant to produce better code
• Unused imports of files defining descriptor extensions will now be reported
• Add proto2::util::RemoveSubranges to remove multiple subranges in linear time.
• Added BaseTextGenerator::GetCurrentIndentationSize()
• Made implicit weak fields compatible with the Apple linker
• Support 32 bit values for ProtoStreamObjectWriter to Struct.
• Removed the internal-only header coded_stream_inl.h and the internal-only methods defined there.
• Enforced no SWIG wrapping of descriptor_database.h (other headers already had this restriction).
• Implementation of the equivalent of the MOMI parser for serialization. This removes one of the two serialization routines, by making the fast array serialization routine completely general. SerializeToCodedStream can now be implemented in terms of the much much faster array serialization. The array serialization regresses slightly, but when array serialization is not possible this wins big.
• Do not convert unknown field name to snake case to accurately report error.
• Fix a UBSAN warnings. (#6333)
• Add podspec for C++ (#6404)
• protoc: fix source code info location for missing label (#6436)
• C++ Add move constructor for Reflection's SetString (#6477)

Java

• Call loadDescriptor outside of synchronized block to remove one possible source of deadlock.
• Have oneof enums implement a separate interface (other than EnumLite) for clarity.
• Opensource Android Memory Accessors
• Update TextFormat to make use of the new TypeRegistry.
• Support getFieldBuilder and getRepeatedFieldBuilder in ExtendableBuilder
• Update JsonFormat to make use of the new TypeRegistry.
• Add proguard config generator for GmmBenchmarkSuiteLite.
• Change ProtobufArrayList to use Object[] instead of ArrayList for 5-10% faster parsing
• Implement ProtobufArrayList.add(E) for 20% (5%-40%) faster overall protolite2 parsing
• Make a copy of JsonFormat.TypeRegistry at the protobuf top level package. This will eventually replace JsonFormat.TypeRegistry.
• Fix javadoc warnings in generated files (#6231)
• Java: Add Automatic-Module-Name entries to the Manifest (#6568)

Python

• Add descriptor methods in descriptor_pool are deprecated.
• Uses explicit imports to prevent multithread test failures in py3.
• Added delitem for Python extension dict
• Update six version to 1.12.0 and fix legacy_create_init issue (#6391)

JavaScript

• Remove deprecated boolean option to getResultBase64String().
• Fix sint64 zig-zag encoding.
• Simplify hash64 string conversion to avoid DIGIT array. Should reduce overhead if these functions aren't used, and be more efficient by avoiding linear array searches.
• Change the parameter types of binaryReaderFn in ExtensionFieldBinaryInfo to (number, ?, ?).
• Create dates.ts and time_of_days.ts to mirror Java versions. This is a near-identical conversion of c.g.type.util.{Dates,TimeOfDays} respectively.
• Migrate moneys to TypeScript.

Ruby

• Fix scope resolution for Google namespace (#5878)
• Support hashes for struct initializers (#5716)
• Optimized away the creation of empty string objects. (#6502)
• Roll forward Ruby upb changes now that protobuf Ruby build is fixed (#5866)
• Optimized layout_mark() for Ruby (#6521)
• Optimization for layout_init() (#6547)
• Fix for GC of Ruby map frames. (#6533)

Other

• Override CocoaPods module to lowercase (#6464)