When Jenkins fails to load plugins, show failures that users need to take action on separate from those due to other plugins failing to load.
(pull 3256)
Upgrade Executable War from 1.36 to 1.37 to allow supplying jenkins.war command-line arguments via standard input using the --paramsFromStdIn parameter.
(pull 3223, documentation)
Jenkins now creates XML 1.1 files to be more accepting of unusual contents.
(issue 48463)
Form validation for number of executors now properly shows validation errors and user-friendly message on form submission.
(issue 47793)
Ensure that threads for background tasks cannot be created with a custom classloader to prevent possible Groovy memory leaks.
(issue 49206)
Upgrade Executable War from 1.36 to 1.37 to prevent multiple copies of winstone-*.jar in the temp folder from using up disk space needlessly.
(issue 22088)
Update to task reactor version 1.5 to prevent hanging of Jenkins on startup/reload when an initialization task throws an unhandled exception.
(issue 48725, full changelog)