fix: dnd freezes an event intermittently (jquense#1631)

* Fixed an issue where dnd freezes an event intermittently

* Make sure OnEnd is called no matter if it's being dragged

Author: zheyujie

src/addons/dragAndDrop/EventContainerWrapper.js

@@ -133,6 +133,7 @@ class EventContainerWrapper extends React.Component {
 
   _selectable = () => {
     let node = findDOMNode(this)
+    let isBeingDragged = false
     let selector = (this._selector = new Selection(() =>
       node.closest('.rbc-time-view')
     ))
@@ -177,16 +178,22 @@ class EventContainerWrapper extends React.Component {
       this.handleDropFromOutside(point, bounds)
     })
 
-    selector.on('selectStart', () => this.context.draggable.onStart())
+    selector.on('selectStart', () => {
+      isBeingDragged = true
+      this.context.draggable.onStart()
+    })
 
     selector.on('select', point => {
       const bounds = getBoundsForNode(node)
-
+      isBeingDragged = false
       if (!this.state.event || !pointInColumn(bounds, point)) return
       this.handleInteractionEnd()
     })
 
-    selector.on('click', () => this.context.draggable.onEnd(null))
+    selector.on('click', () => {
+      if (isBeingDragged) this.reset()
+      this.context.draggable.onEnd(null)
+    })
 
     selector.on('reset', () => {
       this.reset()