Difference in JavaScript support with TC 15.61

I have submitted a case on February, 9, which is still on-going.

After some further tests, the behavior change happened between TC 15.57, and 15.58.

I have submitted a simple reproduction case: a HTML page with some JavaScript elements:

    <script>
var globalVar = "global var";
var obj = { "a": 20, "b" : function() { return "obj.b return"; } };
var editedByEval = 10;
function getSomeValue() { return "get some value"; }
function setEditedByEval(val) { if (val != null) { editedByEval = val; } return editedByEval; }
    </script>

I'm loading the page with Chrome. And there is a JavaScript TestComplete script which accesses these elements (with value check, and exception processing removed):

var page = Sys.Browser("*").WaitPage("*");
var g = page.contentDocument.Script.globalVar;
g = page.contentDocument.Script.obj.a;
g = page.contentDocument.Script.getSomeValue();
g = page.contentDocument.Script.obj.b();
page.contentDocument.Script.eval("setEditedByEval(30);");

Starting with 15.58, all these elements under .Script, are undefined (which might trigger an exception when accessing a sub-object, e.g. ".Script.obj.a")