Variable leaking into global scope

[pigulla]

Consider the following source:

function a() {
    var x;
    function b() {
        x = 42;
    }
}

When I run escope via this script:

var escope = require("escope"),
    esprima = require("esprima");

var src = require("fs").readFileSync("source.js");

var ast = esprima.parse(src),
    scopes = escope.analyze(ast).scopes;

// dump names of variables in the global scope
console.dir(scopes[0].variables.map(function (variable) {
    return variable.name
}));

I get the following outpout: ["a", "x"]

Interestingly, if I change x = 42 to x() or simply x, it does not appear in the output.

Am I using escope incorrectly or why is x in the global scope?

[Constellation]

Nice catch! This is bug.
I'll fix it soon.