Stop tokenizing buffer when it is destroyed

spec/tokenized-buffer-spec.coffee

@@ -26,6 +26,18 @@ describe "TokenizedBuffer", ->
       expect(tokenizedBuffer2.buffer).toBe tokenizedBuffer1.buffer
       expect(tokenizedBuffer2.getTabLength()).toBe tokenizedBuffer1.getTabLength()
 
+  describe "when the buffer is destroyed", ->
+    beforeEach ->
+      buffer = project.bufferForPath('sample.js')
+      tokenizedBuffer = new TokenizedBuffer({buffer})
+      startTokenizing(tokenizedBuffer)
+
+    it "stops tokenization", ->
+      tokenizedBuffer.destroy()
+      spyOn(tokenizedBuffer, 'tokenizeNextChunk')
+      advanceClock()
+      expect(tokenizedBuffer.tokenizeNextChunk).not.toHaveBeenCalled()
+
   describe "when the buffer contains soft-tabs", ->
     beforeEach ->
       buffer = project.bufferForPath('sample.js')

src/tokenized-buffer.coffee

@@ -99,11 +99,11 @@ class TokenizedBuffer
     @trigger "changed", { start: 0, end: lastRow, delta: 0 }
 
   tokenizeInBackground: ->
-    return if not @visible or @pendingChunk
+    return if not @visible or @pendingChunk or @destroyed
     @pendingChunk = true
     _.defer =>
       @pendingChunk = false
-      @tokenizeNextChunk()
+      @tokenizeNextChunk() unless @destroyed
 
   tokenizeNextChunk: ->
     rowsRemaining = @chunkSize
@@ -249,6 +249,7 @@ class TokenizedBuffer
 
   destroy: ->
     @unsubscribe()
+    @destroyed = true
 
   iterateTokensInBufferRange: (bufferRange, iterator) ->
     bufferRange = Range.fromObject(bufferRange)