Projects w/ EditSessions for now-deleted files can now be reloaded w/out error

spec/app/editor-spec.coffee

@@ -74,6 +74,14 @@ describe "Editor", ->
       expect(newEditor.scrollTop()).toBe editor.scrollTop()
       expect(newEditor.scrollView.scrollLeft()).toBe 44
 
+    it "does not blow up if no file exists for a previous edit session, but prints a warning", ->
+      spyOn(console, 'warn')
+      fs.write('/tmp/delete-me')
+      editor.edit(rootView.project.buildEditSessionForPath('/tmp/delete-me'))
+      fs.remove('/tmp/delete-me')
+      newEditor = editor.copy()
+      expect(console.warn).toHaveBeenCalled()
+
   describe "when the editor is attached to the dom", ->
     it "calculates line height and char width and updates the pixel position of the cursor", ->
       expect(editor.lineHeight).toBeNull()

src/app/edit-session.coffee

@@ -9,13 +9,18 @@ EventEmitter = require 'event-emitter'
 Range = require 'range'
 AnchorRange = require 'anchor-range'
 _ = require 'underscore'
+fs = require 'fs'
 
 module.exports =
 class EditSession
   @idCounter: 1
 
   @deserialize: (state, project) ->
-    session = project.buildEditSessionForPath(state.buffer)
+    if fs.exists(state.buffer)
+      session = project.buildEditSessionForPath(state.buffer)
+    else
+      console.warn "Could not build edit session for path '#{state.buffer}' because that file no longer exists"
+      session = project.buildEditSessionForPath(null)
     session.setScrollTop(state.scrollTop)
     session.setScrollLeft(state.scrollLeft)
     session.setCursorScreenPosition(state.cursorScreenPosition)

src/app/project.coffee

@@ -119,8 +119,11 @@ class Project
   bufferForPath: (filePath) ->
     if filePath?
       filePath = @resolve(filePath)
-      buffer = _.find @buffers, (buffer) -> buffer.getPath() == filePath
-      buffer or @buildBuffer(filePath)
+      if filePath
+        buffer = _.find @buffers, (buffer) -> buffer.getPath() == filePath
+        buffer or @buildBuffer(filePath)
+      else
+
     else
       @buildBuffer()