Modular Jar file permissions changed when fixing modification time

[laurentgo]

When a new modular jar file is generated with maven-jar-plugin with Java 11, the final permissions of the file are restricted to the current user instead of using the environment umask which usually allows for group and other users to access the file as well.

This is caused by the use of Files#createTempFile() which has a restrictive file permission model for security reason but as the temporary file is generated next to the original jar file, and there's no sensitive reason to restrict its access, the restrictive file permission should not be needed