OF-646 Made it clear that DateTime.parse() also may return null. Fixed muc/HistoryRequest.java

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@13542 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/openfire/muc/HistoryRequest.java

@@ -182,7 +182,7 @@ public class HistoryRequest {
                     try {
                         // Get the date when the historic message was sent
                         Date delayedDate = xmppDateTime.parseString(delayInformation.attributeValue("stamp"));
-                        if (getSince() != null && delayedDate.before(getSince())) {
+                        if (getSince() != null && delayedDate != null && delayedDate.before(getSince())) {
                             // Stop collecting history since we have exceded a limit
                             break;
                         }

src/java/org/jivesoftware/util/XMPPDateTimeFormat.java

@@ -91,8 +91,11 @@ public class XMPPDateTimeFormat {
      * XEP-0082: CCYY-MM-DDThh:mm:ss[.sss]TZD
      * legacy: CCYYMMDDThh:mm:ss
      * 
-     * @param dateStr
-     * @return
+     * This method either returns a Date instance as result or it will return null or throw a ParseException
+     * in case the String couldn't be parsed.
+     * 
+     * @param dateStr the String that should be parsed
+     * @return the parsed date or null if the String could not be parsed
      * @throws ParseException
      */
     public Date parseString(String dateString) throws ParseException {
@@ -135,8 +138,11 @@ public class XMPPDateTimeFormat {
      * Tries to convert a given string to a Date object.
      * This method only supports the legacy XMPP time format: CCYYMMDDThh:mm:ss
      * 
+     * This method either returns a Date instance as result or it will return null or throw a ParseException
+     * in case the String couldn't be parsed.
+     * 
      * @param dateStr
-     * @return
+     * @return the parsed date or null if the String could not be parsed
      * @throws ParseException
      */
     public Date parseOldDate(String dateStr) throws ParseException {