Index: mozilla/content/base/src/nsXMLHttpRequest.cpp
===================================================================
RCS file: /cvsroot/mozilla/content/base/src/nsXMLHttpRequest.cpp,v
retrieving revision 1.159
diff -pu -r1.159 mozilla/content/base/src/nsXMLHttpRequest.cpp
--- mozilla/content/base/src/nsXMLHttpRequest.cpp
+++ mozilla/content/base/src/nsXMLHttpRequest.cpp
@@ -1533,16 +1533,39 @@ nsXMLHttpRequest::Send(nsIVariant *aBody
 
     if (serial) {
       // Convert to a byte stream
-      nsCOMPtr<nsIScriptableUnicodeConverter> converter =
-        do_CreateInstance("@mozilla.org/intl/scriptableunicodeconverter", &rv);
-      NS_ENSURE_SUCCESS(rv, rv);
-
-      rv = converter->SetCharset("UTF-8");
-      NS_ENSURE_SUCCESS(rv, rv);
-
-      rv = converter->ConvertToInputStream(serial,
-                                           getter_AddRefs(postDataStream));
-      NS_ENSURE_SUCCESS(rv, rv);
+      nsCOMPtr<nsICharsetConverterManager> ccm =
+        do_GetService(NS_CHARSETCONVERTERMANAGER_CONTRACTID, &rv);
+      if (NS_FAILED(rv))
+        return rv;
+
+      nsCOMPtr<nsIUnicodeEncoder> encoder;
+      rv = ccm->GetUnicodeEncoderRaw("UTF-8",
+                                     getter_AddRefs(encoder));
+      if (NS_FAILED(rv))
+        return rv;
+
+      PRInt32 srcLength = serial.Length();
+      PRInt32 outLength = srcLength*6;
+      if (outLength < srcLength)
+        return NS_ERROR_FAILURE;
+
+      char *output = (char*)NS_Alloc(outLength);
+      if (!output)
+        return NS_ERROR_OUT_OF_MEMORY;
+
+      rv = encoder->Convert(serial.get(), &srcLength, output, &outLength);
+      if (NS_SUCCEEDED(rv)) {
+        nsCOMPtr<nsIStringInputStream> stringDataStream =
+          do_CreateInstance(NS_STRINGINPUTSTREAM_CONTRACTID, &rv);
+        postDataStream = stringDataStream;
+        if (postDataStream) {
+          rv = stringDataStream->SetData(output, outLength);
+        }
+      }
+      NS_Free(output);
+
+      if (NS_FAILED(rv))
+        return rv;
     }
 
     if (postDataStream) {