Index: http-utils/src/main/java/com/sun/grizzly/util/http/mapper/Mapper.java
===================================================================
--- http-utils/src/main/java/com/sun/grizzly/util/http/mapper/Mapper.java	(revision 1417)
+++ http-utils/src/main/java/com/sun/grizzly/util/http/mapper/Mapper.java	(working copy)
@@ -182,9 +182,14 @@
         newHost.defaultContexts = defaultContexts;
         newHost.defaultContextPaths = defaultContextPaths;
         // END GlassFish 1024
-        if (insertMap(hosts, newHosts, newHost)) {
+        Host oldElem = (Host) insertMap(hosts, newHosts, newHost);
+        if (oldElem == null) {
             hosts = newHosts;
-        }
+        } else if (allowReplacement) {
+            oldElem.object = host;
+            contextList = oldElem.contextList;
+        } 
+
         for (int i = 0; i < aliases.length; i++) {
             newHosts = new Host[hosts.length + 1];
             newHost = new Host();
@@ -195,7 +200,7 @@
             newHost.defaultContextPaths = defaultContextPaths;
             // END GlassFish 1024
             newHost.object = host;
-            if (insertMap(hosts, newHosts, newHost)) {
+            if (insertMap(hosts, newHosts, newHost) == null) {
                 hosts = newHosts;
             }
         }
@@ -299,7 +304,7 @@
                 newContext.object = context;
                 newContext.welcomeResources = welcomeResources;
                 newContext.resources = resources;
-                if (insertMap(contexts, newContexts, newContext)) {
+                if (insertMap(contexts, newContexts, newContext) == null) {
                     host.contextList.contexts = newContexts;
                     // START GlassFish 1024
                     if (path.equals(host.defaultContextPaths[0])) {
@@ -447,7 +452,7 @@
                 Wrapper[] oldWrappers = context.wildcardWrappers;
                 Wrapper[] newWrappers =
                     new Wrapper[oldWrappers.length + 1];
-                if (insertMap(oldWrappers, newWrappers, newWrapper)) {
+                if (insertMap(oldWrappers, newWrappers, newWrapper) == null) {
                     context.wildcardWrappers = newWrappers;
                     int slashCount = slashCount(newWrapper.name);
                     if (slashCount > context.nesting) {
@@ -460,7 +465,7 @@
                 Wrapper[] oldWrappers = context.extensionWrappers;
                 Wrapper[] newWrappers =
                     new Wrapper[oldWrappers.length + 1];
-                if (insertMap(oldWrappers, newWrappers, newWrapper)) {
+                if (insertMap(oldWrappers, newWrappers, newWrapper) == null) {
                     context.extensionWrappers = newWrappers;
                 }
             } else if (path.equals("/")) {
@@ -473,7 +478,7 @@
                 Wrapper[] oldWrappers = context.exactWrappers;
                 Wrapper[] newWrappers =
                     new Wrapper[oldWrappers.length + 1];
-                if (insertMap(oldWrappers, newWrappers, newWrapper)) {
+                if (insertMap(oldWrappers, newWrappers, newWrapper) == null) {
                     context.exactWrappers = newWrappers;
                 }
             }
@@ -1403,23 +1408,25 @@
 
 
     /**
-     * Insert into the right place in a sorted MapElement array, and prevent
-     * duplicates only if {@link #allowReplacement} is <tt>false</tt>
+     * Insert into the right place in a sorted MapElement array, preventing
+     * duplicates.
+     *
+     * @return old MapElement with matching name (this is an indication that
+     * newElement has not been inserted), or null if oldMap did not contain
+     * any MapElement with matching name (this is an indication that
+     * newElement has been inserted)
      */
-    private static final boolean insertMap
+    private static final MapElement insertMap
         (MapElement[] oldMap, MapElement[] newMap, MapElement newElement) {
         int pos = find(oldMap, newElement.name);
         if ((pos != -1) && (newElement.name.equals(oldMap[pos].name))) {
-            if (allowReplacement){
-                oldMap[pos].object = newElement.object;
-            } 
-            return false;
+            return oldMap[pos];
         }
         System.arraycopy(oldMap, 0, newMap, 0, pos + 1);
         newMap[pos + 1] = newElement;
         System.arraycopy
             (oldMap, pos + 1, newMap, pos + 2, oldMap.length - pos - 1);
-        return true;
+        return null;
     }