Undefined or not initialized variables with strange behavior

[EduFrazao]

Hi. Undefined or not initialized variables presents a strange behavior in version 1.7.14

Like this code:

var x = undefined;

if (!x) {
    // Never enters here
}

Not initialized variables also reports its types as strings

var x;
print(typeof x)

This codes prints: "string"

Is this somehow expected?

Edit note: With 1.7.13 works fine.

[zozo-yasuda]

I tested in the current 1.7.15 snapshot, indeed:

var x = undefined;
if(x) print(x)  //yields nothing
if(!x) print(x) //prints "undefined"

I also checked Boolean(undefined). This evaluates to false as it should, so maybe there's something wrong with the if logic. For the second issue, mine printed undefined so this was probably fixed.

I'll add these as test cases when I familiarize myself more with the repo.

[EduFrazao]

I tested in the current 1.7.15 snapshot, indeed:

var x = undefined;
if(x) print(x)  //yields nothing
if(!x) print(x) //prints "undefined"

I also checked Boolean(undefined). This evaluates to false as it should, so maybe there's something wrong with the if logic. For the second issue, mine printed undefined so this was probably fixed.

I'll add these as test cases when I familiarize myself more with the repo.

Hi. Thanks for testing. Did you test the output of "typeof x" after set it as undefined?

[p-bakker]

@EduFrazao Rhino 1.7.15 had been released.

Could you validate if the issue you had in 1.7.14 is still present our not?

[p-bakker]

If this issue is still present in 1.7.15, it would be great if you could try it before and after the merging of https://github.com/mozilla/rhino/pull/979, which is a merged PR that made changes in the area of undefined handling

[p-bakker]

@gbrail any chance this regression might be due to the changes you made in #979?

[p-bakker]

@gbrail quick ping in case this fell off the bottom of the list 🙂

[gbrail]

I tried this on the master branch and I didn't see the original behavior described, so I'd want to understand what exactly the original poster did to get this result.

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@gbrail https://github.com/gbrail quick ping in case this fell off the bottom of the list 🙂

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[p-bakker]

My bad, I misread the second comment in that I thought it confirmed the bug, but it did the opposite

@EduFrazao please provide more details on how to reproduce or at least how you interact with Rhino/execute your JS code, because we cannot reproduce the behaviour your reporting, neither in master not with the 1.7.14 release

Without a way to reproduce the issue, there's not much we can do with this case