Index: oak-core/src/main/java/org/apache/jackrabbit/oak/security/user/UserProviderImpl.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- oak-core/src/main/java/org/apache/jackrabbit/oak/security/user/UserProviderImpl.java	(date 1345220366000)
+++ oak-core/src/main/java/org/apache/jackrabbit/oak/security/user/UserProviderImpl.java	(revision )
@@ -177,7 +177,7 @@
         this.identifierManager = new IdentifierManager(contentSession, root);
 
         defaultDepth = config.getConfigValue(UserManagerConfig.PARAM_DEFAULT_DEPTH, DEFAULT_DEPTH);
-        int splitValue = config.getConfigValue(UserManagerConfig.PARAM_GROUP_MEMBERSHIP_SPLIT_SIZE, 0);
+        int splitValue = config.getConfigValue(UserManagerConfig.PARAM_GROUP_MEMBERSHIP_SPLIT_SIZE, 4);
         if (splitValue < 4) {
             log.warn("Invalid value {} for {}. Expected integer >= 4", splitValue, UserManagerConfig.PARAM_GROUP_MEMBERSHIP_SPLIT_SIZE);
             splitValue = 0;
@@ -463,7 +463,7 @@
 
     private boolean isAuthorizableTree(Tree tree, int type) {
         // FIXME: check for node type according to the specified type constraint
-        if (tree.hasProperty(JcrConstants.JCR_PRIMARYTYPE)) {
+        if (tree != null && tree.hasProperty(JcrConstants.JCR_PRIMARYTYPE)) {
             String ntName = tree.getProperty(JcrConstants.JCR_PRIMARYTYPE).getValue().getString();
             switch (type) {
                 case UserManager.SEARCH_TYPE_GROUP:
@@ -512,7 +512,7 @@
         NodeUtil folder;
         Tree authTree = root.getTree(authRoot);
         if (authTree == null) {
-            folder = new NodeUtil(root.getTree(""), contentSession);
+            folder = new NodeUtil(root.getTree("/"), contentSession);
             for (String name : Text.explode(authRoot, '/', false)) {
                 folder = folder.getOrAddChild(name, NT_REP_AUTHORIZABLE_FOLDER);
             }
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