ServletDefinition#getPathInfo() logic is broken - triggers Index out of bounds when servlets forward

[gissuebot]

From google.com@cefn.com on December 14, 2010 14:37:28

I am forwarding from one servlet to another which triggers an exception in Guice code.

The request comes in as http://localhost:8080/about which is forwarded to the FreemarkerServlet by
request.getRequestDispatcher("/about.tpl").forward(request, response);
...the pathInfo logic gets confused and tries to retrieve a large section of a zero-length string.

Can anyone tell me how I'm supposed to forward requests as this is definitely broken? Perhaps it's the servlet engine which is broken, but the error turns up in Guice.

Copy-pasting the stack information from a live eclipse debugging session gives you these values...
String "getServletPath()"= "/about.test"
String "getRequestURI()"= "/about.ftl"
String "getContextPath()"= ""

...so clearly the following code in ServletDefinition will throw an array out of bounds.

final int servletPathLength = getServletPath().length();
pathInfo = getRequestURI().substring(getContextPath().length()).replaceAll("[/]{2,}", "/").substring(servletPathLength);

The project is organised as a maven project, managed in eclipse, and is downloadable from  github if more information about configuration is needed. Servlet config is mostly in this directory... https://github.com/cefn/Spring-JPA-MVC-Postgres/tree/1407d2d000aa2f9e964f23406a3aee355de14c00/src/main/java/com/cefn/filesystem/servlet I'm hosting GuiceServlets 3.0-20100927 from the maven groupid com.mycila.com.google.inject.extensions on Jetty 8.0.0M2.

Original issue: http://code.google.com/p/google-guice/issues/detail?id=580

[gissuebot]

From dhanji on December 18, 2010 14:41:59

Can you submit a testcase describing the broken behavior please? Then we can fix it up.

[gissuebot]

From google.com@cefn.com on December 19, 2010 04:16:58

I've drawn out the individual components from the repo I linked to. The forward never completes, so I don't think it matters what 'about.ftl' is bound to.

These lines should only take 30 seconds to copy paste into a working Guice-trunk test environment, but I haven't successfully set one up yet.

>>>>>>>>>>>>

In ServletContextAdaptor. ServletModule $1#configureServlets()...

bind(AboutServlet.class).in(Singleton.class);
serve("/about.test").with(AboutServlet.class);

In AboutServlet#service(HttpServletRequest, HttpServletResponse)...

operations.forward(request, response, "/about.ftl");

...which cashes out in BasicHttpServlet.BasicOperations#forward...

public void forward(HttpServletRequest request, HttpServletResponse response, String path) throws IOException, ServletException{
        request.getRequestDispatcher(path).forward(request, response);
}

<<<<<<<<<<<<<<<<<

I just noticed mccullis' guidance on Guice test cases against my question how to write test cases... https://code.google.com/p/google-guice/issues/detail?id=522#c9 ...and I'll try and schedule the time to work through this next week so I can commit a proper failing test case if copy pasting those lines doesn't recreate.

[gissuebot]

From google.com@cefn.com on December 19, 2010 04:20:14

Forgot to say you would need to visit http://localhost:8080/about.test in order to recreate the exception, not http://localhost:8080/about as per my original errored description. That's why proper test cases are better!

[gissuebot]

From cefn@cefn.com on December 21, 2010 05:01:24

I checked out the trunk build and tried to write a testcase.

I had a hard time rcreating exactly the logic of Jetty through Mock objects as I simply don't know what this logic is. The logic which steers things is principally about setting named Attributes in the request and I can't find the right order to recreate the routing and trigger the fail.

Nevertheless it seems to be an established problem. I found another example of it... http://groups.google.com/group/google-guice/browse_thread/thread/9e360e237d8ad6eb?pli=1

[gissuebot]

From sberlin on February 21, 2011 17:45:17

(No comment was entered for this change.)

Labels: Extension-Servlet