Subjects from windowToggle continue forever

[SephVelut]

Bug Report

Current Behavior
Each returned Subject on windowToggle continues forever after closingSelector emits when the closingSelector is a stream from another windowToggle.

Reproduction

// <div id="zone1"><div id="zone2"></div></div>
const zone1 = document.getElementById("zone1") // not null
const zone2 = document.getElementById("zone2") // not null

const zone1Down = fromEvent(zone1, 'mousedown')
const zone1Move = fromEvent(zone1, 'mousemove')
const zone1Up = fromEvent(zone1, 'mouseup')

const zone2Move = fromEvent(zone2, 'mousemove')

const zone1Window = merge(zone1Down, zone1Move, zone1Up)
    .pipe(windowToggle(zone1Down, (_: any) => zone1Up))
    .pipe(share())

const opener = zone1Window
    .pipe(map(s => s.pipe(take(1))) // take the first in each windowed stream
    .pipe(flatMap(e => e))

const closer = zone1Window
    .pipe(map(s => s.pipe(takeLast(1))) // take the last in each windowed stream
    .pipe(flatMap(e => e))

// The issue happens here
zone2Move
   .pipe(windowToggle(opener, (_: any) => closer))
   .pipe(flatMap(e => e))
   .subscribe(console.log)

When the zone1 div is clicked down and held then zone2Move starts emitting movement from zone2 div. All good. Releasing the mouse to activate zone1Up to emit, which causes the closer to emit which should cause the subject emitted by zone2Move to stop emitting, but the subject continues to emit.

Changing the last windowToggle code to this

zone2Move
   .pipe(windowToggle(zone1Down, (_: any) => zone1Up))
   .pipe(flatMap(e => e))
   .subscribe(console.log)

Exhibits the correct behavior. Subjects from zone2Move stop emitting after zone1Up emits. But I don't see the difference between the two windowing methods. zone1Down and opener are emitting the same thing, same time. As are zone1Up and closer. This leads me to believe there is inconsistent behavior with windowToggle

Environment

• Runtime: Chrome 79.0.3945.79
• RxJS version: 6.5.3

[cartant]

Can the example be simplified? I don't understand why the zone1Down, zone1Move and zone1Up observables are merged here. There will be two subscription to the zone1Down: for the source in the merge and for the opening notifier to windowToggle.

Why is this necessary? What behaviour were you expecting to see here?

const zone1Window = merge(zone1Down, zone1Move, zone1Up)
    .pipe(windowToggle(zone1Down, (_: any) => zone1Up))
    .pipe(share())

[cartant]

Closing this 'cause no simplified reproduction - or explanation - was provided.