See gh-23884

Closes gh-23879

- Add maxInMemorySize property to Decoder and HttpMessageReader
  implementations that aggregate input to trigger
  DataBufferLimitException when reached.

- For codecs that call DataBufferUtils#join, there is now an overloaded
  variant with a maxInMemorySize extra argument. Internally, a custom
  LimitedDataBufferList is used to count and enforce the limit.

- Jackson2Tokenizer and XmlEventDecoder support those limits per
  streamed JSON object.

- Configurable limits for multipart requests with Synchronoss NIO.

- Centralized maxInMemorySize exposed via CodecConfigurer along with
  ability to plug in an instance of MultipartHttpMessageWrite.

Closes gh-23884

Bypass server cookie and write Set-Cookie header directly for Reactor
Netty, and Servlet API which do not provide options.

For Undertow use the sameSite attribute.

Closes gh-23693

Fixes gh-23631

See gh-23539
Co-authored-by: NSam Brannen <sbrannen@pivotal.io>

See: gh-23553

On a Servlet container a completion notification may come at any time
even in the UNSUBSCRIBED state, i.e. before the write Publisher has
called onSubscribe.

See: gh-23553

Prior to this commit, the entry set of read-only HttpHeaders lost the
original headers' ordering.

The changes in commit ce7278aa introduced a regression in the read-only
HttpHeaders support. Specifically, the implementation of entrySet() in
the internal ReadOnlyHttpHeaders class converted the original entry set
to an immutable, non-ordered set of immutable entries.

This commit fixes this issue by converting the original entry set to an
immutable, ordered set of immutable entries.

Closes gh-23551

Closes gh-23518

Follow-up change in addition to dd22b8fd.

See gh-23096

Closes gh-23096

Closes gh-23484

See gh-23366

Added support for status codes that do not occur in HttpStatus in
DefaultClientResponseBuilder and made ClientResponse::statusCode
ClientHttpResponse::getStatusCode @Nullable.

Closed gh-23366

Prior to this commit, the `header(String, String)` method in the
ServerHttpRequest.Builder API actually added a header value instead of
setting or overriding a header value. Since this conflicted with the
stated behavior in the Javadoc as well as the original intention of the
method, we have decided to introduce an overloaded variant
`header(String, String...)` which accepts a var-args list of header
values to set or override.

In addition, this commit deprecates the existing `header(String, String)`
method for removal in Spring Framework 5.2.

In order not to be a breaking change for custom implementations of the
builder API, this commit implements the new `header(String, String...)`
method as an interface `default` method, with the intent to remove the
default implementation in Spring Framework 5.2

closes gh-23333

See gh-23353

Closes gh-23278

Prior to Spring Framework 5.1.3, MimeTypeUtils.parseMimeTypes() and
MediaType.parseMediaTypes() ignored empty entries, but 5.1.3 introduced
a regression in that an empty entry -- for example, due to a trailing
comma in the list of media types in an HTTP Accept header -- would result
in a "406 Not Acceptable" response status.

This commit fixes this by filtering out empty entries before parsing
them into MimeType and MediaType instances. Empty entries are therefore
effectively ignored.

Fixes gh-23241

Closes gh-23175

Closes gh-23153

Improve Javadoc
Consistently reject Publisher unless using asyncPart
Consistently set Content-Type when specified

Closes gh-23077

Closes gh-23051

Closes gh-22982

Closes gh-22976

Closes gh-22952

Closes gh-22936

Closes gh-22931

Closes gh-22506

This commit adds proper reference counting to the UndertowDataBuffer.

Closes gh-22747