Destroy unretained buffers when serializing project

Previously buffers could linger indefinitely if an error occurred
during startup between the deserialization of the project and the
original retaining edit session.

spec/project-spec.coffee

@@ -8,6 +8,13 @@ describe "Project", ->
   beforeEach ->
     project.setPath(project.resolve('dir'))
 
+  describe "serialization", ->
+    it "destroys unretained buffers and does not include them in the serialized state", ->
+      project.bufferForPath('a')
+      expect(project.getBuffers().length).toBe 1
+      expect(deserialize(project.serialize()).getBuffers().length).toBe 0
+      expect(project.getBuffers().length).toBe 0
+
   describe "when an edit session is destroyed", ->
     it "removes edit session and calls destroy on buffer (if buffer is not referenced by other edit sessions)", ->
       editSession = project.open("a")

src/project.coffee

@@ -91,9 +91,14 @@ class Project
   serialize: ->
     state = @state.clone()
     state.set('path', @getPath())
+    @destroyUnretainedBuffers()
     state.set('buffers', buffer.serialize() for buffer in @getBuffers())
     state
 
+  # Private:
+  destroyUnretainedBuffers: ->
+     buffer.destroy() for buffer in @getBuffers() when not buffer.isRetained()
+
   # Public: ?
   getState: -> @state
 

src/text-buffer.coffee

@@ -81,13 +81,15 @@ class TextBuffer
       @destroyed = true
       @project?.removeBuffer(this)
 
+  isRetained: -> @refcount > 0
+
   retain: ->
     @refcount++
     this
 
   release: ->
     @refcount--
-    @destroy() if @refcount <= 0
+    @destroy() unless @isRetained()
     this
 
   serialize: ->