From 1764677b7d039fbcbd9febef550703b2b9a1c04c Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Wed, 19 Jun 2013 09:53:41 -0700
Subject: [PATCH] Unsubscribe markers when destroying display buffer

Previously the display buffer markers would still fire events
even after a display buffer was destroyed since they were not
being unsubscribed from their underlying buffer marker which
could still fire events in the case of an editor split on the
same buffer.

Closes #593
---
 spec/app/display-buffer-spec.coffee  | 7 +++++++
 src/app/display-buffer-marker.coffee | 7 +++++--
 src/app/display-buffer.coffee        | 8 ++++++--
 3 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/spec/app/display-buffer-spec.coffee b/spec/app/display-buffer-spec.coffee
index c02f334c6..d460aa5b9 100644
--- a/spec/app/display-buffer-spec.coffee
+++ b/spec/app/display-buffer-spec.coffee
@@ -532,6 +532,13 @@ describe "DisplayBuffer", ->
       buffer.delete([[6, 0], [6, 65]])
       expect(displayBuffer.getMaxLineLength()).toBe 62
 
+  describe ".destroy()", ->
+    it "unsubscribes all display buffer markers from their underlying buffer marker (regression)", ->
+      marker = displayBuffer.markBufferPosition([12, 2])
+      displayBuffer.destroy()
+      expect(marker.bufferMarker.subscriptionCount()).toBe 0
+      expect( -> buffer.insert([12, 2], '\n')).not.toThrow()
+
   describe "markers", ->
     beforeEach ->
       displayBuffer.createFold(4, 7)
diff --git a/src/app/display-buffer-marker.coffee b/src/app/display-buffer-marker.coffee
index 02b8996f5..4fd3f9689 100644
--- a/src/app/display-buffer-marker.coffee
+++ b/src/app/display-buffer-marker.coffee
@@ -1,6 +1,7 @@
 Range = require 'range'
 _ = require 'underscore'
 EventEmitter = require 'event-emitter'
+Subscriber = require 'subscriber'
 
 module.exports =
 class DisplayBufferMarker
@@ -131,6 +132,7 @@ class DisplayBufferMarker
   # Destroys the marker
   destroy: ->
     @bufferMarker.destroy()
+    @unsubscribe()
 
   # Returns a {String} representation of the marker
   inspect: ->
@@ -143,11 +145,11 @@ class DisplayBufferMarker
     @trigger 'destroyed'
 
   observeBufferMarker: ->
-    @bufferMarker.on 'destroyed', => @destroyed()
+    @subscribe @bufferMarker, 'destroyed', => @destroyed()
 
     @getHeadScreenPosition() # memoize current value
     @getTailScreenPosition() # memoize current value
-    @bufferMarker.on 'changed', ({oldHeadPosition, newHeadPosition, oldTailPosition, newTailPosition, bufferChanged, valid}) =>
+    @subscribe @bufferMarker, 'changed', ({oldHeadPosition, newHeadPosition, oldTailPosition, newTailPosition, bufferChanged, valid}) =>
       @notifyObservers
         oldHeadBufferPosition: oldHeadPosition
         newHeadBufferPosition: newHeadPosition
@@ -192,3 +194,4 @@ class DisplayBufferMarker
     }
 
 _.extend DisplayBufferMarker.prototype, EventEmitter
+_.extend DisplayBufferMarker.prototype, Subscriber
diff --git a/src/app/display-buffer.coffee b/src/app/display-buffer.coffee
index 9d2fae945..0a1d98da1 100644
--- a/src/app/display-buffer.coffee
+++ b/src/app/display-buffer.coffee
@@ -393,9 +393,12 @@ class DisplayBuffer
   #
   # Returns the {DisplayBufferMarker} (if it exists).
   getMarker: (id) ->
-    @markers[id] ?= do =>
+    marker = @markers[id]
+    unless marker?
       if bufferMarker = @buffer.getMarker(id)
-        new DisplayBufferMarker({bufferMarker, displayBuffer: this})
+        marker = new DisplayBufferMarker({bufferMarker, displayBuffer: this})
+        @markers[id] = marker
+    marker
 
   # Retrieves the active markers in the buffer.
   #
@@ -492,6 +495,7 @@ class DisplayBuffer
       marker.notifyObservers(bufferChanged: false)
 
   destroy: ->
+    marker.unsubscribe() for marker in @getMarkers()
     @tokenizedBuffer.destroy()
     @unsubscribe()