jdk/src/java.base/share/classes/sun/launcher/resources/launcher.properties is a good example to explain the issue. The resources used to create usage messages (java.launcher.opt.footer and java.launcher.X.usage) are multi-line resources. This makes it easy to see changes with diff tools and webrev. It also make it easy to edit the file.

The translated resources are missing the line breaks. Reviewers on jdk9-dev pointed this out when attempting to review translation of this and other resources. In addition to diffs being difficult, it makes it really hard to edit the translated resources when that need arises.

This issue is a request for the translation system to preserve the line breaks so that the translated resources can be compared (webrev) or edited to fix bugs.