Trouble with binary expression in doc generation

[jrozentur]

I am trying to return a document to the rest call. The document contains results of a match array, and a binary conclusion

> accept[result]{
 c=3
 a=[1,2,3]
 result={"v":a}
}
Rule 'accept' defined in package repl. Type 'show' to see rules.
> accept
[
  {
    "v": [
      1,
      2,
      3
    ]
  }
]

This is correct, but let's add a conditional:

> accept[result]{
 c=3
 a=[1,2,3]
 result={"ok":c==0, "v":a}
}
Rule 'accept' defined in package repl. Type 'show' to see rules.
> accept
[]

Why is the resulting doc empty? c is a bound variable, and I should be able to use it in an expression, the problem is when the expression is binary

[tsandall]

Under the hood, OPA is rewriting the == operation as a unification operation without checking whether the result of the == operation is required. Unification fails (since 3 != 0) so the query ends up undefined. This is a bug. Thanks for reporting it--it should be a quick fix.