Fix corner cases related to lifecycle state of EditorComponent on events

Signed-off-by: Max Brunsfeld <maxbrunsfeld@gmail.com>

src/scrollbar-component.coffee

@@ -38,6 +38,9 @@ ScrollbarComponent = React.createClass
 
     @getDOMNode().addEventListener 'scroll', @onScroll
 
+  componentWillUnmount: ->
+    @getDOMNode().removeEventListener 'scroll', @onScroll
+
   shouldComponentUpdate: (newProps) ->
     return true if newProps.visible isnt @props.visible
 

src/text-editor-component.coffee

@@ -435,7 +435,8 @@ TextEditorComponent = React.createClass
       @refs.input.focus()
 
   blurred: ->
-    @setState(focused: false)
+    if @isMounted()
+      @setState(focused: false)
 
   onTextInput: (event) ->
     event.stopPropagation()

src/text-editor-element.coffee

@@ -111,7 +111,7 @@ class TextEditorElement extends HTMLElement
 
   blurred: (event) ->
     unless atom.config.get('editor.useShadowDOM')
-      if event.relatedTarget is @component?.refs.input.getDOMNode()
+      if event.relatedTarget is @component?.refs.input?.getDOMNode()
         event.stopImmediatePropagation()
         return