Add tests to defend against bad TZDB versions

Ensure that Oslo, Stockholm and Amsterdam still resolve correctly
Any user picking up an invalid TZDB file should see a failure

src/test/java/org/joda/time/TestDateTimeZone.java

@@ -38,15 +38,15 @@
 import java.util.Set;
 import java.util.TimeZone;
 
-import junit.framework.TestCase;
-import junit.framework.TestSuite;
-
 import org.joda.time.tz.DefaultNameProvider;
 import org.joda.time.tz.NameProvider;
 import org.joda.time.tz.Provider;
 import org.joda.time.tz.UTCProvider;
 import org.joda.time.tz.ZoneInfoProvider;
 
+import junit.framework.TestCase;
+import junit.framework.TestSuite;
+
 /**
  * This class is a JUnit test for DateTimeZone.
  *
@@ -106,13 +106,16 @@ public class TestDateTimeZone extends TestCase {
  static {
  // don't call Policy.getPolicy()
  RESTRICT = new Policy() {
+ @Override
  public PermissionCollection getPermissions(CodeSource codesource) {
  Permissions p = new Permissions();
  p.add(new AllPermission()); // enable everything
  return p;
  }
+ @Override
  public void refresh() {
  }
+ @Override
  public boolean implies(ProtectionDomain domain, Permission permission) {
  if (permission instanceof JodaTimePermission) {
  return false;
@@ -122,11 +125,13 @@ public boolean implies(ProtectionDomain domain, Permission permission) {
  }
  };
  ALLOW = new Policy() {
+ @Override
  public PermissionCollection getPermissions(CodeSource codesource) {
  Permissions p = new Permissions();
  p.add(new AllPermission()); // enable everything
  return p;
  }
+ @Override
  public void refresh() {
  }
  };
@@ -147,12 +152,14 @@ public TestDateTimeZone(String name) {
  super(name);
  }
 
+ @Override
  protected void setUp() throws Exception {
  locale = Locale.getDefault();
  zone = DateTimeZone.getDefault();
  Locale.setDefault(Locale.UK);
  }
 
+ @Override
  protected void tearDown() throws Exception {
  Locale.setDefault(locale);
  DateTimeZone.setDefault(zone);
@@ -243,6 +250,12 @@ public void testForID_String() {
  } catch (IllegalArgumentException ex) {}
  }
 
+ public void testForID_ensureTzdb() {
+ assertEquals("Europe/Oslo", DateTimeZone.forID("Europe/Oslo").getID());
+ assertEquals("Europe/Stockholm", DateTimeZone.forID("Europe/Stockholm").getID());
+ assertEquals("Europe/Amsterdam", DateTimeZone.forID("Europe/Amsterdam").getID());
+ }
+
  public void testForID_String_old() {
  Map<String, String> map = new LinkedHashMap<String, String>();
  map.put("GMT", "UTC");
@@ -706,24 +719,31 @@ public void testConstructor() {
  assertTrue(Modifier.isProtected(DateTimeZone.class.getDeclaredConstructors()[0].getModifiers()));
  try {
  new DateTimeZone(null) {
+ @Override
  public String getNameKey(long instant) {
  return null;
  }
+ @Override
  public int getOffset(long instant) {
  return 0;
  }
+ @Override
  public int getStandardOffset(long instant) {
  return 0;
  }
+ @Override
  public boolean isFixed() {
  return false;
  }
+ @Override
  public long nextTransition(long instant) {
  return 0;
  }
+ @Override
  public long previousTransition(long instant) {
  return 0;
  }
+ @Override
  public boolean equals(Object object) {
  return false;
  }
@@ -845,24 +865,31 @@ static class MockDateTimeZone extends DateTimeZone {
  public MockDateTimeZone(String id) {
  super(id);
  }
+ @Override
  public String getNameKey(long instant) {
  return null; // null
  }
+ @Override
  public int getOffset(long instant) {
  return 0;
  }
+ @Override
  public int getStandardOffset(long instant) {
  return 0;
  }
+ @Override
  public boolean isFixed() {
  return false;
  }
+ @Override
  public long nextTransition(long instant) {
  return 0;
  }
+ @Override
  public long previousTransition(long instant) {
  return 0;
  }
+ @Override
  public boolean equals(Object object) {
  return false;
  }