Merge branch '1.4.x' into 1.5.x

spring-boot-docs/src/main/asciidoc/howto.adoc

@@ -2200,6 +2200,12 @@ The master change log is by default read from `db/changelog/db.changelog-master.
 can be set using `liquibase.change-log`. In addition to YAML, Liquibase also supports
 JSON, XML, and SQL change log formats.
 
+By default Liquibase will autowire the (`@Primary`) `DataSource` in your context and use
+that for migrations. If you like to use a different `DataSource` you can create one and
+mark its `@Bean` as `@LiquibaseDataSource` - if you do that remember to create another one
+and mark it as `@Primary` if you want two data sources. Or you can use Liquibase's native
+`DataSource` by setting `liquibase.[url,user,password]` in external properties.
+
 See
 {sc-spring-boot-autoconfigure}/liquibase/LiquibaseProperties.{sc-ext}[`LiquibaseProperties`]
 for details of available settings like contexts, default schema etc.

spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -4921,6 +4921,16 @@ namespace, see the
 {sc-spring-boot-autoconfigure}/mail/MailProperties.{sc-ext}[`MailProperties`] for more
 details.
 
+In particular, certain default timeout values are infinite and you may want to change that
+to avoid having a thread blocked by an unresponsive mail server:
+
+[source,properties,indent=0]
+----
+	spring.mail.properties.mail.smtp.connecttimeout=5000
+	spring.mail.properties.mail.smtp.timeout=3000
+	spring.mail.properties.mail.smtp.writetimeout=5000
+----
+
 
 
 [[boot-features-jta]]