Prompt to save dirty buffers from destroyEditSessionIndex

Previously only the active editor session was prompting to
save dirty buffers before closing.  This caused the confirm
dialog to not display when closing from a tab since the
Editor.destroyEditSessionIndex is used there.

spec/app/editor-spec.coffee

@@ -2043,6 +2043,17 @@ describe "Editor", ->
       editor.underlayer.trigger event
       expect(editor.getSelection().getScreenRange()).toEqual [[0,0], [12,2]]
 
+  describe ".destroyEditSessionIndex(index)", ->
+    it "prompts to save dirty buffers before closing", ->
+      editor.setText("I'm dirty")
+      rootView.open('sample.txt')
+      expect(editor.getEditSessions().length).toBe 2
+      spyOn(atom, "confirm")
+      editor.destroyEditSessionIndex(0)
+      expect(atom.confirm).toHaveBeenCalled
+      expect(editor.getEditSessions().length).toBe 2
+      expect(editor.getEditSessions()[0].buffer.isModified()).toBeTruthy()
+
   describe ".destroyInactiveEditSessions()", ->
     it "destroys all non-active, non-modified edit sessions", ->
       editor.setText("I'm dirty")

src/app/editor.coffee

@@ -148,7 +148,7 @@ class Editor extends View
         'core:select-down': @selectDown
         'core:select-to-top': @selectToTop
         'core:select-to-bottom': @selectToBottom
-        'core:close': @close
+        'core:close': @destroyActiveEditSession
         'editor:save': @save
         'editor:newline-below': @insertNewlineBelow
         'editor:toggle-soft-tabs': @toggleSoftTabs
@@ -448,15 +448,21 @@ class Editor extends View
     @destroyEditSessionIndex(@getActiveEditSessionIndex())
 
   destroyEditSessionIndex: (index) ->
-    if @editSessions.length == 1
-      @remove()
-    else
-      editSession = @editSessions[index]
+    return if @mini
+
+    editSession = @editSessions[index]
+    destroySession = =>
       if index is @getActiveEditSessionIndex()
         @loadPreviousEditSession()
       _.remove(@editSessions, editSession)
       editSession.destroy()
       @trigger 'editor:edit-session-removed', [editSession, index]
+      @remove() if @editSessions.length is 0
+
+    if editSession.buffer.isModified()
+      @promptToSaveDirtySession(editSession, destroySession)
+    else
+      destroySession(editSession)
 
   destroyInactiveEditSessions: ->
     index = 0
@@ -634,14 +640,14 @@ class Editor extends View
       @removeClass 'soft-wrap'
       $(window).off 'resize', @_setSoftWrapColumn
 
-  save: (onSuccess) ->
+  save: (session=@activeEditSession, onSuccess) ->
     if @getPath()
-      @activeEditSession.save()
+      session.save()
       onSuccess?()
     else
       atom.showSaveDialog (path) =>
         if path
-          @activeEditSession.saveAs(path)
+          session.saveAs(path)
           onSuccess?()
 
   autosave: ->
@@ -679,19 +685,16 @@ class Editor extends View
   rootView: ->
     @parents('#root-view').view()
 
-  close: ->
-    return if @mini
-    if @getBuffer().isModified()
-      filename = if @getPath() then fs.base(@getPath()) else "untitled buffer"
-      atom.confirm(
-        "'#{filename}' has changes, do you want to save them?"
-        "Your changes will be lost if you don't save them"
-        "Save", (=> @save(=> @destroyActiveEditSession())),
-        "Cancel", null
-        "Don't save", (=> @destroyActiveEditSession())
-      )
-    else
-      @destroyActiveEditSession()
+  promptToSaveDirtySession: (session, callback) ->
+    path = session.getPath()
+    filename = if path then fs.base(path) else "untitled buffer"
+    atom.confirm(
+      "'#{filename}' has changes, do you want to save them?"
+      "Your changes will be lost if you don't save them"
+      "Save", => @save(session, callback),
+      "Cancel", null
+      "Don't save", callback
+    )
 
   remove: (selector, keepData) ->
     return super if keepData