* commit '42b5c369cd0559025938d07c73ca51d1c0c32f2e':
  Allow for ref-type arrays containing null elements.

* commit '8a15121c1077fe883f428bd27dee6b99e06e48b6':
  Allow for ref-type arrays containing null elements.

Strip the null elements out before serializing the array.
This is helpful in the cases where the user wants to construct
an array of an inexact size for serialization. For example:
User constructs array of size 5 because they anticipate adding
more than 1 element before serialization. Only 3 get added, so
the array looks like [Obj, Obj, Obj, null, null]. This would
curently crash without this CL.

All repeated fields of ref-type elements can contain null
elements: repeated strings, repeated bytes, and repeated
messages/groups.

Change-Id: I117391c868c9a436536d70d6151780e9cc7e8227

Conflicts:
	src/google/protobuf/compiler/javanano/javanano_message_field.cc

* commit '72fa49d45452418ca7365b97af9e7d426d535916':
  Implement hashCode() and equals() behind a generator option.

* commit 'bb971d53626cb286f8dc491c15d2731001c4891b':
  Implement hashCode() and equals() behind a generator option.

The option is only called 'generate_equals' because:
- equals() is the main thing; hashCode() is there only to
  complement equals();
- it's shorter;
- toString() should not be included in this option because
  it's more for debugging and it's more likely to stop
  ProGuard from working well.

Also shortened the "has bit" expression; was
((bitField & mask) == mask), now ((bitField & mask) != 0).
Both the Java code and the bytecode are slightly shorter.

Change-Id: Ic309a08a60883bf454eb6612679aa99611620e76

* commit '7cb6b37f3799affce9e1be39977d4419283df795':
  Feature request: set() and clear() accessors return this

* commit '42be1e79ccd670be36220222936aa7cacc6856f6':
  Feature request: set() and clear() accessors return this

Also pre-inlines set() and has() in serialization code. This could
theoretically help ProGuard: the message class size is usually large,
and because of this only, it may refuse to inline an accessor into
the serialization code, and as a result keeps the accessor intact.
Chances are, after pre-inlining all accessor calls within the message
class, those accessors become unused or single-use, so there are more
reasons for ProGuard to inline and then remove them.

Change-Id: I57decbe0b2533c1be21439de0aad15f49c7024dd

* commit 'd52f7a3e2f3d4dba9b8c134dc2fa2a54ddd1ce17':
  Make generated code more aligned with Google Java style.

* commit 'c50f605c572a425b2fa696fedc5e61ac6f66d2a9':
  Make generated code more aligned with Google Java style.

- Blank line after opening a message class (but not an enum interface).
- Let all code blocks insert blank lines before themselves. This applies to
  'package' statement, all message classes, enum classes or constant groups,
  extensions, bitfields, proto fields (one block per field; i.e. accessors
  don't have blank lines among them), and basic MessageNano methods. In this
  case we don't need to guess what the next block is and create blank lines
  for it.
- Fixed some newline/indent errors.
- Only one SuppressWarnings("hiding") per file.

Change-Id: I865f52ad4fb6ea3b3a98b97ac9d78d19fc46c858

* commit '5b4b84a18dc04b1b6c931c42403731fa79eb213d':
  Fix repeated field merging semantics.

* commit 'afaf74ce55f4aff63dc30e7045a7cd6c1cf232dc':
  Fix repeated field merging semantics.

The public doc states that repeated fields are simply concatenated
and doesn't impose a different semantics for packed fields. This
CL fixes this for packed fields and adds tests covering all cases.

Also fixed a bit of missed null-repeated-field treatments.

Change-Id: Ie35277bb1a9f0b8171dc9d07b6adf9b9d3308de2

* commit 'bf222b76dc346d3946a701ba675a7c31833f81fc':
  Protect against null repeated fields.

* commit '63e819adbb4d2d8215f5d3d8297dc50bf2fe3329':
  Protect against null repeated fields.

* commit '051ea13ce26ff0ff9dbc487c2b233b0159204e40':

* commit 'c85806baedfc98ad5759a990b35ea5b5f1ac4edb':

There's no distinction between a repeated field being null and being
empty. In both cases, nothing is sent on the wire. Clients might for
whatever reason inadvertently set a repeated field to null, so
protect against that and treat it just as if the field was empty.

Change-Id: Ic3846f7f2189d6cfff6f8ef3ca217daecc3c8be7

* commit '145af9e8915a5e814d5deba8bcea68d066dd7f9e':
  Remove all field initializers and let ctor call clear().

* commit '39cee9f1f5cd513a53ac5100eb208ed431f99af0':
  Remove all field initializers and let ctor call clear().

The field initializers have basically caused the compiled <init> method
to inline the whole clear() method, which means if ProGuard is not used
or failed to inline or remove clear(), there are two big chunks of code
that do the same thing. So why not just call clear() from the ctor.

Change-Id: Ief71e2b03db2e059b3bfa98309649368089ffab0

* commit '7457ebc9ae3eee30ccb44f259a14316e7d9ab950':
  Add missing README parts for enum_style and in-repo usage

* commit 'cbb08132821cb56f4e6c5e5f8a0b32f51879782a':
  Add missing README parts for enum_style and in-repo usage

Change-Id: I7934a5b0444017aeda787501ebf8d9f9ba295c73

* commit '570db0e9bdfb7c2696dcd6c31483223cc2d1c4f3':
  Add reftypes field generator option.

* commit 'c4a1b547c91178d79f5d2cc2e00b8be922c22fe8':
  Add reftypes field generator option.

* commit 'fdbd1e42d8fdfde0efc3ed3d31f0ee95f5e324ac':
  Fix some indenting issues with set__() function

* commit '44cbb06c725fbba00464bba9f19dc0ea295406b1':
  Fix some indenting issues with set__() function