Domain double-pop

domain-test.js

var domain = require('domain')
  , d1 = new domain.Domain()
  , d2 = new domain.Domain()
  , d3 = new domain.Domain()
  , d4 = new domain.Domain()

console.log("Starting: ", domain._stack)
d1.enter()
console.log("Entered d1: ", domain._stack)
d2.enter()
console.log("Entered d2: ", domain._stack)
d3.enter()
console.log("Entered d3: ", domain._stack)
d2.exit()
console.log("Exitted d2: ", domain._stack)
d2.exit()
console.log("Exitted d2 again: ", domain._stack)

d1.enter()
d2.enter()
d3.enter()
console.log("Re-entered d1, d2, d3: ", domain._stack)
d4.exit()
console.log("Exitted unused d4: ", domain._stack)

output.txt

Starting:  []
Entered d1:  [ { domain: null, _events: {}, _maxListeners: 10, members: [] } ]
Entered d2:  [ { domain: null, _events: {}, _maxListeners: 10, members: [] },
  { domain: null, _events: {}, _maxListeners: 10, members: [] } ]
Entered d3:  [ { domain: null, _events: {}, _maxListeners: 10, members: [] },
  { domain: null, _events: {}, _maxListeners: 10, members: [] },
  { domain: null, _events: {}, _maxListeners: 10, members: [] } ]
Exitted d2:  [ { domain: null, _events: {}, _maxListeners: 10, members: [] } ]
Exitted d2 again:  []
Re-entered d1, d2, d3:  [ { domain: null, _events: {}, _maxListeners: 10, members: [] },
  { domain: null, _events: {}, _maxListeners: 10, members: [] },
  { domain: null, _events: {}, _maxListeners: 10, members: [] } ]
Exitted unused d4:  []