* Add source code URI to the Ruby gemspec file

As a developer, I would like to easily find the source code origin for this gem when browsing through https://rubygems.org/gems/google-protobuf.
In order to solve this, I've followed instructions at https://guides.rubygems.org/specification-reference/#metadata by adding the source_code_uri metadata key pair.

* Use git tag instead of fixed "master" string

* Substitute the string, not the Gem::Version

Proto2 has been tested for invalid cases. Check implementation of
ExpectParseFailureForProto (https://github.com/protocolbuffers/protobuf/blob/master/conformance/binary_json_conformance_suite.cc#L322)

Fix for race in lazy initialization of handlers.

Optimized layout_mark() for Ruby

This fixes https://github.com/protocolbuffers/protobuf/issues/6532.

Archive is declared in the protobuf_deps() call above

When the @six//:six library is used on a target without the
`legacy_create_init` flag disabled, the library will not be
usable due to __init__.py being empty and the six code will
be in six.py. This change forces six to occupy the __init__
name, preventing this file getting created regardless of
the `legacy_create_init` setting.

See comments on a74c43bb for
context:
https://github.com/protocolbuffers/protobuf/commit/a74c43bbd906a42b6bf70668c5d515c6f1d8d2cb

Signed-off-by: DNKpp <dnkpp2011@gmail.com>

* Rolled forward again with "Updated upb from defcleanup branch..."

Revert "Revert "Updated upb from defcleanup branch and modified Ruby to use it (#5539)" (#5848)"

This reverts commit 1568deab.

* A few more merge fixes.

* Updated for defcleanup2 branch.

* Fixed upb to define upb_decode().

* Fixed names of nested messages.

* Revert submodule.

* Set -std=gnu90 and fixed warnings/errors.

Some of our Kokoro tests seem to run with this level of warnings,
and the source strives to be gnu90 compatible.  Enforcing it for
every build removes the possibility of some errors showing up in
Kokoro/Travis tests only.

* Fixed remaining warnings with gnu90 mode.

I tried to match warning flags with what Ruby appears to do
in our Kokoro tests.

* Initialize values registered by rb_gc_register_address().

* Fixed subtle GC bug.

We need to initialize this marked value before creating the instance.

* Truly fix the GC bug.

* Updated upb for mktime() fix.

* Removed XOPEN_SOURCE as we are not using strptime().

* Removed fixed tests from the conformance failure list for Ruby.

* Fixed memory error related to oneof def names.

* Picked up new upb changes re: JSON printing.

* Uncomment concurrent decoding test.

Optimized away the creation of empty string objects.

Prior to this CL, creating an empty message object would create
two empty string objects for every declared field.  First we
created a unique string object for the field's default.  Then
we created yet another string object when we assigned the
default value into the message: we called #encode to ensure
that the string would have the correct encoding and be frozen.

I optimized these unnecessary objects away with two fixes:

1. Memoize the empty string so that we don't create a new empty
   string for every field's default.
2. If we are assigning a string to a message object, avoid creating
   a new string if the assigned string has the correct encoding and
   is already frozen.

* Add changelog for 3.9.x

* Revert "Make php message class final to avoid mocking (#6277)" (#6324)

This reverts commit 7f84a943.
This is just temporary. Eventually, we still want to roll forward this
change. Some users are complaining they need more time to clean up their
code.

* Update extract_includes.bat.in

File io_win32.h is not in directory google\protobuf\stubs under directory google\protobuf\io

* Set oneof case in array constructor (#6351)

Forgot to set it previously.

* Update protobuf version (#6366)

* Drop building wheel for python 3.4 (#6406)

https://github.com/matthew-brett/multibuild/pull/240

* Fix binary compatibility in FieldCodec factory methods (#6380) (#6424)

* Fix binary compatibility in FieldCodec factory messages

* Make default value parameter for current factories required

* Route old methods through default value overloads

* Remove ExtensionRegistry.Add(params) overload

* Rename ExtensionRegistry.Add(IEnumerable<Extension>) overload to AddRange

* Edit naming of parameters in Extension classes

* * Fix add API warnings to docs for extension APIs
* Rename internal ExtensionSet.GetValue to TryGetValue

* Disable javadoc error (#6371)

* Disable javadoc error

Actual fixes of the javadoc will be followed up

* Remove duplicated configuration

* Update javadoc plugin version

* Updated Bazel test script to use most recent Bazel version (#6413) (#6433)

I'm not exactly sure why, but this fixes the failing Bazel presubmit
test. Using the most recent version seems like a good idea anyway so
that we can make sure we're compatible with any new Bazel changes.

* [bazel] Add fixes for --incompatible_load_{cc,java,proto}_rules_from_bzl

* No need to update version in generated code (#6471)

generate_descriptor will handle that

* Update protobuf version (#6472)

* No free when construct was not done

This fix the segfault when some other error happens

* Add more tests

* Use Sub to avoid printing too much

Fix #3218

This reverts commit dcc8ffd9.

* Add conformance tests for explicit packed/unpacked fields

* Fix typo

* Update failure lists

* Update failure list

* Use enum class to make enum scoped

* compatibility tests between last released and the current version

This change adds the required loads to examples and zlib.
For full compatibility with --incompatible_load_{cc,java,proto}_rules_from_bzl,
we will need to roll gtest to a newer version.

Windows: expand path names on command line

* Add binary conformance test for default repeated fields

1) Both packed and unpacked encoding should be accepted for parsing.
2) Encode should follow the default way for the syntax.

* Uncomment test

* Remove is_primitive

* Add failed tests to failure lists.

* Add failed test to failure list

* Use binary format to specify expected value

Text format cannot distinguish whether repeated field is packed or not.

* Change method name from ToHexString to ToOctString

* Add failed test to failure list

* Add failed test to php's failure list

* Fix comments

* Add csharp compatibility tests for 3.7.0

* Add compatibility test between last major version with current for C#

* Update last version number

* compatibility tests between last released and the current version

* fix typo

* support hashes for struct initalizers

* convert hash keys to string

* update tests

* add extra asserts