Leaf 3 seems to return true for #if(somevar) even when somevar isn't set

[twostraws]

Leaf 2 allowed us to check whether a variable was set in the current context by writing #if(somevar), but in Leaf 3 this no longer works.

To reproduce the problem, creating the following Leaf template:

#if(haters) {
    <p>The "haters" variable is set to #(haters)</p>
}

#if(fakers) {
    <p>The "fakers" variable is set to #(fakers)</p>
}

If you render that template with the context ["haters": "hating"] you would expect the first message to be printed but not the second, but as of 3.0 alpha 4 both messages are printed.

[twostraws]

This was resolved in later alphas.