Bug 31556 Export jar from Navigator view fails
(M5 build) In Navigator view (resource perspective), right-click on a src/ directory containing your sources, select export->jar file and the package selector opens with no resource selected (and finish button disabled); but it seems that the src/ dir is really selected, because if you re-select it in the window, it ends up with a "jar creation failed" and a lot of duplicate entries in the error log. If you try the same from the Projects view (Java browsing perspective), it works fine.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/jarpackager/JarPackageWizardPage.java
}
	/**
	 * Hook method for subclasses to persist their settings.
	 */
	protected void internalSaveWidgetValues() {
	}
	/**
	 *	Hook method for restoring widget values to the values that they held
	 *	last time this wizard was used to completion.
	 */
	protected void restoreWidgetValues() {
		if (!((JarPackageWizard)getWizard()).isInitializingFromJarPackage())
			initializeJarPackage();
		fExportClassFilesCheckbox.setSelection(fJarPackage.areClassFilesExported());
		fExportJavaFilesCheckbox.setSelection(fJarPackage.areJavaFilesExported());
		
		if (fJarPackage.getJarLocation().isEmpty())
			fDestinationNamesCombo.setText(""); 
		else
			fDestinationNamesCombo.setText(fJarPackage.getJarLocation().toOSString());
		IDialogSettings settings= getDialogSettings();
		if (settings != null) {
			String[] directoryNames= settings.getArray(STORE_DESTINATION_NAMES);
			if (directoryNames == null)
				return; 
			if (! fDestinationNamesCombo.getText().equals(directoryNames[0]))
				fDestinationNamesCombo.add(fDestinationNamesCombo.getText());
			for (int i= 0; i < directoryNames.length; i++)
				fDestinationNamesCombo.add(directoryNames[i]);
		}