Details
Major Description
In LocalizedResourceFilter, there is code that looks for a localized copy of a resource. Here is an example snippet that gives rise to the exception (around line 185):
String filePath = filterConfig.getServletContext().getRealPath(path);
if (new File(filePath).exists())
return context + path;
According to the javadoc for ServletContext.getRealPath(), it is allowed to return null if the file does not exist. As my widgets are not localized, this is the case, and a NullPointerException occurs because null is then passed to new File(filePath).
I'm not sure why this has not been found before - perhaps other web servers have been returning non-null if a resource does not exist.
I've fixed it temporarily with a local patch that does an extra null check before calling new File():
String filePath = filterConfig.getServletContext().getRealPath(path);
if (filePath != null && new File(filePath).exists())
return context + path;
I will attach a patch file since there are 3 places in the file using getRealPath().