Index: jspwiki-war/src/main/java/org/apache/wiki/auth/SessionMonitor.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- jspwiki-war/src/main/java/org/apache/wiki/auth/SessionMonitor.java	(revision be183fc4eaa304fd357163d23e1d433b5f131abb)
+++ jspwiki-war/src/main/java/org/apache/wiki/auth/SessionMonitor.java	(revision )
@@ -201,9 +201,10 @@
     public final Principal[] userPrincipals()
     {
         Collection<Principal> principals = new ArrayList<Principal>();
-        for ( WikiSession session : m_sessions.values() )
-        {
-            principals.add( session.getUserPrincipal() );
+        synchronized ( m_sessions ) {
+            for (WikiSession session : m_sessions.values()) {
+                principals.add( session.getUserPrincipal() );
+            }
         }
         Principal[] p = principals.toArray( new Principal[principals.size()] );
         Arrays.sort( p, m_comparator );
Index: ChangeLog
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- ChangeLog	(revision be183fc4eaa304fd357163d23e1d433b5f131abb)
+++ ChangeLog	(revision )
@@ -1,3 +1,9 @@
+2017-05-14  Harry Metske (metskem@apache.org)
+
+       * 2.10.3-git-39
+
+       * JSPWIKI-1059 - ConcurrentModificationException in SessionMonitor
+
 2017-04-22  Dirk Frederickx (brushed AT apache DOT org)
 
        * 2.10.3-git-38  Haddock Template updates
Index: jspwiki-war/src/main/java/org/apache/wiki/Release.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- jspwiki-war/src/main/java/org/apache/wiki/Release.java	(revision be183fc4eaa304fd357163d23e1d433b5f131abb)
+++ jspwiki-war/src/main/java/org/apache/wiki/Release.java	(revision )
@@ -72,7 +72,7 @@
      *  <p>
      *  If the build identifier is empty, it is not added.
      */
-    public static final String     BUILD         = "38";
+    public static final String     BUILD         = "39";
 
     /**
      *  This is the generic version string you should use when printing out the version.  It is of