drupal.js issue with JSON response - causes upload to hang

After hours I figured out what is the real problem in my issue http://drupal.org/node/55355 and this one http://drupal.org/node/53314.

It causes an upload to hang at least in Firefox 1.0.7 after you press 'attach' in the upload form. It will cause all other things to fail that use the 'redirectFormButton' function in drupal.js.

The problem is with a strange behaviour of eval() in this browser. If the string passed to eval() contains a literal string that in turn contains a newline or a carriage return (a real one, not a quoted one) then eval() gives an 'unlimited string literal' error.

Example (where [newline] is the newline character):
eval('({"status": true, "data": "abcdefg[newline]hijklmn"})');
will give an 'unlimited string literal' error.

So here is my patch (sorry, no patch file but it's only two new lines):

This block starting at 140

        // Get response from iframe body
        try {
          response = (iframe.contentWindow || iframe.contentDocument || iframe).document.body.innerHTML;
          if (window.opera) {
            // Opera-hack: it returns innerHTML sanitized.
            response = response.replace(/"/g, '"');
          }
        }

has to be changed to this one

        // Get response from iframe body
        try {
          response = (iframe.contentWindow || iframe.contentDocument || iframe).document.body.innerHTML;
          response = response.replace(/\n/g, "\\n");
          response = response.replace(/\r/g, "\\r");
          if (window.opera) {
            // Opera-hack: it returns innerHTML sanitized.
            response = response.replace(/"/g, '"');
          }
        }

This will replace newlines and carriage returns with quoted ones.