[2.3.x] + (additional commit for) fix issue #1663

https://java.net/jira/browse/GRIZZLY-1663
"NPE when registering a servlet in grizzly-httpservice"

Author: oleksiys

extras/grizzly-httpservice/src/main/java/org/glassfish/grizzly/osgi/httpservice/OSGiCleanMapper.java

@@ -271,11 +271,22 @@ public List<OSGiServletHandler> getContext(HttpContext httpContext) {
         return contextServletHandlerMap.get(httpContext);
     }
 
-    public void addContext(HttpContext httpContext, List<OSGiServletHandler> servletHandlers) {
-        contextServletHandlerMap.put(httpContext, servletHandlers);
-        httpContextToServletContextMap.put(httpContext, new OSGiServletContext(httpContext, logger));
+    public void addContext(final HttpContext httpContext,
+            final List<OSGiServletHandler> servletHandlers) {
+        addContext(httpContext, null, servletHandlers);
     }
 
+    public void addContext(final HttpContext httpContext,
+            OSGiServletContext servletCtx,
+            final List<OSGiServletHandler> servletHandlers) {
+        if (servletCtx == null) {
+            servletCtx = new OSGiServletContext(httpContext, logger);
+        }
+        
+        contextServletHandlerMap.put(httpContext, servletHandlers);
+        httpContextToServletContextMap.put(httpContext, servletCtx);
+    }
+    
     public OSGiServletContext getServletContext(final HttpContext httpContext) {
         return httpContextToServletContextMap.get(httpContext);
     }

extras/grizzly-httpservice/src/main/java/org/glassfish/grizzly/osgi/httpservice/OSGiMainHandler.java

@@ -459,7 +459,9 @@ private OSGiServletHandler findOrCreateOSGiServletHandler(
             }
 
             servletHandlers = new ArrayList<OSGiServletHandler>(1);
-            mapper.addContext(httpContext, servletHandlers);
+            mapper.addContext(httpContext,
+                    mapper.getServletContext(httpContext),
+                    servletHandlers);
 
             final OSGiServletContext servletContext =
                     mapper.getServletContext(httpContext);
@@ -474,7 +476,6 @@ private OSGiServletHandler findOrCreateOSGiServletHandler(
                                            logger);
             servletHandlers.add(osgiServletHandler);
             osgiServletHandler.setFilterChainFactory(servletContext.getFilterChainFactory());
-
         }
 
         return osgiServletHandler;