"ignore-rhs" causes weird failures

[pgsandstrom]

Bug Report

• TSLint version: 5.16.0
• TypeScript version: 3.3.4000
• Running TSLint via: CLI

TypeScript code being linted

let bool1:boolean = true
let bool2:boolean = true
let obj:{}|undefined = {}

const func = () => {
  if(bool1 && obj && bool2) {
    return 1
  } else {
    return 2
  }
}

with tslint.json configuration:

{
  "rules": {
    "strict-boolean-expressions": [true, "allow-undefined-union", "ignore-rhs"]
  }
}

Actual behavior

Get error This type is not allowed in the operand for the '&&' operator because it unions more than one truthy/falsy type. Allowed types are boolean or undefined-union.

Expected behavior

It should pass. If I remove "ignore-rhs" from tslint.json it passes.