Passing the make file content to drush_make_parse_info_file breaks the converter

If i run drush convert-makefile old.make new.make I get the content of old.make and following error printed on my screen:

failed to open stream: No such file or directory drush_make.utilities.inc:385

and the converter stops working.

This happens because the function read in drush_make_d_o.convert.inc calls
drush_make_parse_info_file(drush_make_get_data($this->from))
but drush_make_parse_info_file($makefile) is also calling drush_make_get_data($makefile) but in this case $makefile is already the file content.