Add hasNewCredentials() function to avoid uselessly hammering on auth logic.

guacamole/src/main/java/net/sourceforge/guacamole/net/basic/AuthenticatingHttpServlet.java

@@ -200,6 +200,17 @@ public abstract class AuthenticatingHttpServlet extends HttpServlet {
         return (UserContext) session.getAttribute(CONTEXT_ATTRIBUTE);
     }
 
+    /**
+     * Returns whether the request given has updated credentials. If this
+     * function returns false, the UserContext will not be updated.
+     * 
+     * @param request The request to check for credentials.
+     * @return true if the request contains credentials, false otherwise.
+     */
+    protected boolean hasNewCredentials(HttpServletRequest request) {
+        return true;
+    }
+    
     @Override
     protected void service(HttpServletRequest request, HttpServletResponse response)
     throws IOException, ServletException {
@@ -247,7 +258,7 @@ public abstract class AuthenticatingHttpServlet extends HttpServlet {
             }
 
             // Otherwise, update existing context
-            else
+            else if (hasNewCredentials(request))
                 context = authProvider.updateUserContext(context, credentials);
 
             // If no context, fail authentication, notify listeners

guacamole/src/main/java/net/sourceforge/guacamole/net/basic/BasicGuacamoleTunnelServlet.java

@@ -251,5 +251,17 @@ public class BasicGuacamoleTunnelServlet extends AuthenticatingHttpServlet {
 
     };
 
+    @Override
+    protected boolean hasNewCredentials(HttpServletRequest request) {
+
+        String query = request.getQueryString();
+        if (query == null)
+            return false;
+
+        // Only connections are given new credentials
+        return query.equals("connect");
+
+    }
+
 }