Index: oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/multiplex/SimpleMountInfoProvider.java
===================================================================
--- oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/multiplex/SimpleMountInfoProvider.java	(revision 1752245)
+++ oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/multiplex/SimpleMountInfoProvider.java	(working copy)
@@ -84,6 +84,16 @@
         return mounts;
     }
 
+    @Override
+    public boolean isMounted(Mount mount, String path) {
+        for (MountInfo md : mountInfos) {
+            if (md.getMount().equals(mount)) {
+                return md.isMounted(path);
+            }
+        }
+        return false;
+    }
+
     //~----------------------------------------< builder >
 
     public static Builder newBuilder(){
Index: oak-core/src/main/java/org/apache/jackrabbit/oak/spi/mount/MountInfoProvider.java
===================================================================
--- oak-core/src/main/java/org/apache/jackrabbit/oak/spi/mount/MountInfoProvider.java	(revision 1752245)
+++ oak-core/src/main/java/org/apache/jackrabbit/oak/spi/mount/MountInfoProvider.java	(working copy)
@@ -45,9 +45,15 @@
         public boolean hasNonDefaultMounts() {
             return false;
         }
-        
+
+        @Override
         public Collection<Mount> getMountsPlacedUnder(String path) {
             return Collections.emptySet();
+        }
+
+        @Override
+        public boolean isMounted(Mount m, String path) {
+            return true;
         };
     };
 
@@ -79,12 +85,17 @@
      * Return true if there are explicit mounts configured
      */
     boolean hasNonDefaultMounts();
-    
+
     /**
      * Returns all mounts placed under the specified path
      * 
      * @param path the path under which mounts are to be found
      * @return a collection of mounts, possibly empty
      */
-    Collection<Mount> getMountsPlacedUnder(String path);    
+    Collection<Mount> getMountsPlacedUnder(String path);
+
+    /**
+     * Return true if the given mount includes the given path
+     */
+    boolean isMounted(Mount m, String path);
 }