Function name scope problem

[RuralHunter]

This code snippet:

function e()
{
    console.log("f="+f);
    if(!f)
    {
        function f(){}
    }
}

var f=function(){};
e();

In Chrome, the output is "f=undefined". In HtmlUnit, the output is "f=function(){}".

[RuralHunter]

Just found if I set the optimization level of the context to 0 or above, I can get the same result as Chrome.

[rbri]

Sounds strange will have a look over the weekend

[RuralHunter]

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function#conditionally_created_functions

[RuralHunter]

Based on the link above, the example can be simplified:

console.log("foo="+foo);
if (false) {
  function foo(){ return 1; }
}

[RuralHunter]

It seems the declaration of 'foo' is removed here:

before transform:
SCRIPT [source name: /varscope.js] [encoded source length: 52] [base line: 1] [end line: 5] [scope #1: foo ] 1
    EXPR_RESULT 1
        CALL 1
            NAME print 1
            ADD
                STRING foo=
                NAME foo 1
    BLOCK 3

SCRIPT [source name: /varscope.js] [encoded source length: 52] [base line: 1] [end line: 5] [scope #1: foo ] 1
    EXPR_RESULT 1
        CALL 1
            NAME print 1
            ADD
                STRING foo=
                NAME foo 1
    BLOCK 3

FUNCTION foo [source name: /varscope.js] [encoded source length: 18] [base line: 4] [end line: 4] 4
    BLOCK 4
        RETURN 4
            NUMBER 1.0 4

after transform:
SCRIPT [source name: /varscope.js] [encoded source length: 52] [base line: 1] [end line: 5] [scope #1: foo ] 1
    EXPR_RESULT 1
        CALL 1
            NAME print 1
            ADD
                STRING foo=
                NAME foo 1
    BLOCK 3

[RuralHunter]

Maybe not. It seems the tree printed out is not quite complete.

[RuralHunter]

I found the key point. The function definition is skipped here in runtime. Apparently InterpretedFunction.hasFunctionNamed(name) does not do what its name implies. It returns false for functions declared with expression, returns true otherwise, event it's not a function at all. I changed InterpretedFunction.hasFunctionNamed to simply return a fixed true and then the script runs same with browsers. I don't see any other problem with that change but I might miss something else since I'm not familiar with Rhino.

[rbri]

Hi @RuralHunter,
sorry but this get lost a bit - looks like your findings are correct, will try to get the fix into the Rhino codebase soon.
(mozilla/rhino#1318)

[RuralHunter]

Great and thanks as always.

[rbri]

see #755