Bug 30382 Incosistent dialog UI when specifying different output locations per source folder
Please see attached image. The dialog says ".. enter a path _RELATIVE_ to 'path/to/sourcefolder'" but the "Browse" dialog generates a path that is relative to sourcefolder parent. It should be clarified, which path will be expected! I suggest removing the current confusing behavior and replace it with a consistent behavior of project relative pathes. I assume a project relative path is stored in the IClasspathEntry anyway.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/OutputLocationDialog.java
public void dialogFieldChanged(DialogField field) {
			doStatusLineUpdate();
		}
		public void changeControlPressed(DialogField field) {
			doChangeControlPressed();
		}
	}
	
	protected void doChangeControlPressed() {
		IContainer container= chooseOutputLocation();
		if (container != null) {
			fContainerDialogField.setText(container.getProjectRelativePath().toString());
		}