SEC-328: Avoid unnecessarily hitting backend a second time, if the cache wasn't used in first place.

core/src/main/java/org/acegisecurity/providers/dao/AbstractUserDetailsAuthenticationProvider.java

@@ -145,10 +145,15 @@ public abstract class AbstractUserDetailsAuthenticationProvider implements Authe
         try {
             additionalAuthenticationChecks(user, (UsernamePasswordAuthenticationToken) authentication);
         } catch (AuthenticationException exception) {
-            // There was a problem, so try again after checking we're using latest data
+        	if(cacheWasUsed) {
+                // There was a problem, so try again after checking
+        		// we're using latest data (ie not from the cache)
                 cacheWasUsed = false;
                 user = retrieveUser(username, (UsernamePasswordAuthenticationToken) authentication);
                 additionalAuthenticationChecks(user, (UsernamePasswordAuthenticationToken) authentication);
+        	} else {
+        		throw exception;
+		    }
         }
 
         if (!user.isCredentialsNonExpired()) {