A fix for OF-1041

Made a search by distinguishedName Active Directory specific
as it is difficult to come up with a generic solution.

src/java/org/jivesoftware/openfire/ldap/LdapGroupProvider.java

@@ -226,8 +226,12 @@ public class LdapGroupProvider extends AbstractGroupProvider {
         Pattern pattern =
                 Pattern.compile("(?i)(^" + manager.getUsernameField() + "=)([^,]+)(.+)");
 
+        // We have to process Active Directory differently.
+        boolean isAD = manager.getUsernameField().equals("sAMAccountName");
+        String[] returningAttributes = isAD ? new String[] { "distinguishedName", manager.getUsernameField() } : new String[] { manager.getUsernameField() };
+        
         SearchControls searchControls = new SearchControls();
-        searchControls.setReturningAttributes(new String[] { "distinguishedName", manager.getUsernameField() });
+        searchControls.setReturningAttributes(returningAttributes);
         // See if recursive searching is enabled. Otherwise, only search one level.
         if (manager.isSubTreeSearch()) {
             searchControls.setSearchScope(SearchControls.SUBTREE_SCOPE);
@@ -289,6 +293,7 @@ public class LdapGroupProvider extends AbstractGroupProvider {
                                 while(usrAnswer.hasMoreElements()) {
                                     searchResult = (SearchResult) usrAnswer.nextElement();
                                     Attributes attrs = searchResult.getAttributes();
+                                    if (isAD) {
                                         Attribute userdnAttr = attrs.get("distinguishedName");
                                         if (username.equals((String)userdnAttr.get())) {
                                             // Exact match found, use it.
@@ -296,6 +301,12 @@ public class LdapGroupProvider extends AbstractGroupProvider {
                                             break;
                                         }
                                     }
+                                    else {
+                                        // No iteration occurs here, which is probably a bug.
+                                        username = (String)attrs.get(manager.getUsernameField()).get();
+                                        break;
+                                    }
+                                }
                             }
                             // Close the enumeration.
                             usrAnswer.close();