This commit harmonizes the change made to @DefaultValue to the
annotation processor. If such annotation is added to a scalar value with
no value at all, no default value is produced.

Closes gh-18917

Closes gh-21061

Closes gh-21052

Update `NettyWebServer` so that the `PortInUseException` is not thrown
for permission denied errors.

Fixes gh-19807

Update classes that throw `PortInUseException` so that they also
include the cause. Prior to this commit the cause was not included
which could make diagnosing the real cause difficult.

See gh-19807

Fixes gh-20745

When using constructor binding, if no properties are bound to
a nested property, the top-level instance will be created with a
null value for the nested property.
This commit introduces support for an empty `@DefaultValue` which
indicates that an instance of the nested property must be created
even if nothing is bound to it. It honors any `@DefaultValue`
annotations that the nested property might have in its constructor.

Closes gh-18917

Update `ConditionalOnAvailableEndpoint` so that it now uses the same
matching code as the endpoint filter. This allows the condition to
match endpoint IDs that contain a dash.

In order to share logic, the `ExposeExcludePropertyEndpointFilter` class
has been deprecated and its logic moved to a new `expose` package
under `IncludExcludeEndpointFilter`. This filter is used by both the
`OnAvailableEndpointCondition` and the auto-configuration classes.

Fixes gh-21044

Closes gh-21039

Closes gh-21027

Update the reference documentation with more details about how relaxed
binding works against environment variables.

Closes gh-18215

Closes gh-21025

Closes gh-19972

Fix checkstyle issues from forward merge.

See gh-21022

Closes gh-21022

Update `ExposeExcludePropertyEndpointFilter` so that patterns will
also match endpoint IDs that contain a dash.

Closes gh-20997

This commit makes sure that both the getter and the setter of a
deprecated configuration properties is flagged with `@Deprecated`.

Closes gh-20812

Closes gh-21003

Refine `DataSourceAutoConfiguration` conditions so that an empty
`spring.datasource.url` property can be used to enable the embedded
source.

Fixed gh-20996

Closes gh-20979

Closes gh-20978

Closes gh-20981

Closes gh-20976

* pr/20882:
  Polish "Polish JarFile to extra anonymous inner class"
  Polish JarFile to extra anonymous inner class

Closes gh-20882

See gh-20882

See gh-20882

Closes gh-20963

Closes gh-20623

See gh-20952

See gh-20950

See gh-20948

See gh-20946

See gh-20944

See gh-20942

Prior to this commit, the Undertow compression configuration provided by
Spring Boot would fail and throw an exception for invalid MIME Types
when trying to check them against the list of configured types for
compression.

This commit ensures that invalid MIME Types are ignored and that
compression is disabled for those.

Fixes gh-20955

See gh-20941

See gh-20940

See gh-20939