Fixes NullPointerException in OptionsRenderer
https://issues.apache.org/jira/browse/TILES-598
This closes #14

Patch by Christian Schuster


git-svn-id: https://svn.apache.org/repos/asf/tiles/framework/trunk@1840285 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/tiles-extras/src/main/java/org/apache/tiles/extras/renderer/OptionsRenderer.java b/tiles-extras/src/main/java/org/apache/tiles/extras/renderer/OptionsRenderer.java
index c728736..b387fd7 100644
--- a/tiles-extras/src/main/java/org/apache/tiles/extras/renderer/OptionsRenderer.java
+++ b/tiles-extras/src/main/java/org/apache/tiles/extras/renderer/OptionsRenderer.java
@@ -190,7 +190,8 @@
 
 
         static boolean attemptTemplate(final String template) {
-            return !TEMPLATE_EXISTS.containsKey(template) || TEMPLATE_EXISTS.get(template);
+            Boolean found = TEMPLATE_EXISTS.get(template);
+            return found == null || found;
         }
 
         static void update(final String template, final boolean found) {