Proposed patch: allow relative URIs

["Schwartz, Todd" <to...@intel.com>]

Hi, all.

Here is a patch that will allow Xerces to validate relative URIs as valid
uriReference values. The second part of the patch, in the
readers.DefaultHandler class, will handle the case where a relative URI is
specified as the system id -- it will force the URI to be resolved before
the system id target is retrieved.

Comments? Questions?


In org.apache.xerces.utils.URI:
===============================

    private void initialize(URI p_base, String p_uriSpec) throws
MalformedURIException {
        if (p_base == null && 
            (p_uriSpec == null || p_uriSpec.trim().length() == 0)) {
            throw new MalformedURIException(
                "Cannot initialize URI with empty parameters.");
        }

        // just make a copy of the base if spec is empty
        if (p_uriSpec == null || p_uriSpec.trim().length() == 0) {
            initialize(p_base);
            return;
        }

        String uriSpec = p_uriSpec.trim();
        int uriSpecLen = uriSpec.length();
        int index = 0;

        // Check for scheme, which must be before `/'. Also handle names
with
        // DOS drive letters ('D:'), so 1-character schemes are not allowed.
        int colonIdx = uriSpec.indexOf(':');
+       if (colonIdx != -1)
+       {
            if ((colonIdx < 2) || (colonIdx > uriSpec.indexOf('/'))) { 
                int fragmentIdx = uriSpec.indexOf('#');
                // A standalone base is a valid URI according to spec
                if (p_base == null && fragmentIdx != 0 ) {
                    throw new MalformedURIException("No scheme found in
URI.");
                }
            }
		else {
                initializeScheme(uriSpec);
                index = m_scheme.length()+1;
            }
+       }

        ...


	
In org.apache.xerces.readers.DefaultHandler:
============================================

    private String expandSystemId(String systemId, String currentSystemId) {
        String id = systemId;

        // check for bad parameters id
        if (id == null || id.length() == 0) {
            return systemId;
        }

        // if id already expanded, return
        try {
            URI uri = new URI(id);
+           if (uri != null && uri.getScheme() != null) {
-           if (uri != null) {
                return systemId;
            }
        }
        catch (URI.MalformedURIException e) {
            // continue on...
        }

        ...