Bug 11317 Won't export some files to .jar.
Create a new java project called "Foo". In the file system, create a folder named "Foo scripts", and in this folder create a file named "foo.txt". Drag this folder into the eclipse packages view and add it to the "Foo" project. Now try to export the project "Foo" to a .jar file. Only the manifest file shows up, even if the file "foo.txt" is checked!
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/jarpackager/JarFileExportOperation.java
}
			progressMonitor.done();
		}
	}
	
	protected boolean preconditionsOK() {
		if (!fJarPackage.areClassFilesExported() && !fJarPackage.areJavaFilesExported()) {
			addError(JarPackagerMessages.getString("JarFileExportOperation.noExportTypeChosen"), null); 
			return false;
		}
		if (fJarPackage.getSelectedElements() == null || fJarPackage.getSelectedElements().size() == 0) {
			addError(JarPackagerMessages.getString("JarFileExportOperation.noResourcesSelected"), null); 
			return false;
		}
		if (fJarPackage.getJarLocation() == null) {
			addError(JarPackagerMessages.getString("JarFileExportOperation.invalidJarLocation"), null); 
			return false;
		}
		if (!fJarPackage.doesManifestExist()) {
			addError(JarPackagerMessages.getString("JarFileExportOperation.manifestDoesNotExist"), null); 
			return false;
		}
		if (!fJarPackage.isMainClassValid(new BusyIndicatorRunnableContext())) {
			addError(JarPackagerMessages.getString("JarFileExportOperation.invalidMainClass"), null); 
			return false;
		}
		IEditorPart[] dirtyEditors= JavaPlugin.getDirtyEditors();
		if (dirtyEditors.length > 0) {
			List unsavedFiles= new ArrayList(dirtyEditors.length);
			List selection= fJarPackage.getSelectedResources();