Please describe the problem:
When I tried to copy a file from an http:// source to a file:// destination, the progress callback passed to g_file_copy was receiving total_num_bytes equals to 0 every time.

So after a little debugging we saw copy_stream_with_progress calling g_file_input_stream_query_info and it was always returning NULL. We tracked the problem to gvfs/daemon/soup-input-stream.c but it wasn't implementing query_info and we didn't find a way to implement because it extends GInputStream, not GFileInputStream.

The way we found to fix it was get the info from GFile with g_file_query_info in copy_stream_with_progress instead of using g_file_input_stream_query_info, since the former implements query_info correctly for the http backend.

Steps to reproduce:
  g_message ("file copy");
  {
    GFile *src;
    GFile *dst;
    GError *error = NULL;

    src = g_file_new_for_uri ("http://lincoln.alfaiati.net/index.html");
    dst = g_file_new_for_uri ("file:///home/lincoln/Desktop/lincoln-alfaiati.html");

    void progress_callback (goffset current_num_bytes, goffset total_num_bytes, gpointer user_data)
    {   
      g_message ("%d, %d", (gint) current_num_bytes, (gint) total_num_bytes);
    }   

    if (!g_file_copy (src, dst, G_FILE_COPY_OVERWRITE, NULL, progress_callback, NULL, &error))
      {   
        g_printerr ("Error... Oh caraio! %s\n", error->message);
        g_error_free (error);
        return 1;
      }   
    return 0;
  }

Actual results:
** Message: file copy
** Message: 1120, 0
** Message: 6912, 0
** Message: 7468, 0
** Message: 7468, 0

Expected results:
** Message: file copy
** Message: 1120, 7468
** Message: 6912, 7468
** Message: 7468, 7468
** Message: 7468, 7468

Does this happen every time?
yes

Other information: