bug 305243 set an XML content-type hint on XMLHttpRequest channels, to always

parse local files as XML.
Also, make TestXMLExtras convert non-ASCII bytes to UTF-16 correctly.
r=jst sr=bz

extensions/xmlextras/base/src/nsXMLHttpRequest.cpp

@@ -1579,6 +1579,11 @@ nsXMLHttpRequest::Send(nsIVariant *aBody)
     listener = this;
   }
 
+  // Since we expect XML data, set the type hint accordingly
+  // This means that we always try to parse local files as XML
+  // ignoring return value, as this is not critical
+  mChannel->SetContentType(NS_LITERAL_CSTRING("application/xml"));
+
   // Start reading from the channel
   ChangeState(XML_HTTP_REQUEST_SENT);
   rv = mChannel->AsyncOpen(listener, nsnull);

extensions/xmlextras/tests/TestXMLExtras.cpp

@@ -57,6 +57,7 @@
 #include <nsIDOMLoadListener.h>
 #include "nsContentCID.h"
 #include "nsReadableUtils.h"
+#include "nsNativeCharsetUtils.h"
 static NS_DEFINE_CID( kXMLDocumentCID, NS_XMLDOCUMENT_CID );
 
 #if 0
@@ -152,7 +153,8 @@ int main (int argc, char* argv[])
                                      &rv );
 
       if (NS_SUCCEEDED( rv )) {
-        nsString str; str.AssignWithConversion(argv[2]);
+        nsString str;
+        NS_CopyNativeToUnicode(nsDependentCString(argv[2]), str);
         rv = pDOMParser->ParseFromString(str.get(), "application/xml",
                                           getter_AddRefs( pDOMDocument ) );