Fire 'modified-status-changed' events on changes after save/reload

Buffer keeps state about the value with which it fired the last
modified-status-changed event so that it doesn't fire it twice with the
same boolean value. Every piece of code that triggers the event also
needs to set this state, so now everything goes through the
`triggerModifiedStatusChanged` method.

spec/app/buffer-spec.coffee

@@ -181,7 +181,7 @@ describe 'Buffer', ->
         changeHandler.callCount > 0
 
   describe "modified status", ->
-    it "reports a modified status of true after the user changes buffer", ->
+    it "reports the modified status changing to true or false after the user changes buffer", ->
       modifiedHandler = jasmine.createSpy("modifiedHandler")
       buffer.on 'modified-status-changed', modifiedHandler
 
@@ -203,7 +203,7 @@ describe 'Buffer', ->
       advanceClock(buffer.stoppedChangingDelay)
       expect(modifiedHandler).toHaveBeenCalledWith(false)
 
-    it "reports a modified status of true after the underlying file is deleted", ->
+    it "reports the modified status changing to true after the underlying file is deleted", ->
       buffer.release()
       filePath = "/tmp/atom-tmp-file"
       fs.write(filePath, 'delete me')
@@ -216,7 +216,7 @@ describe 'Buffer', ->
       waitsFor "modified status to change", -> modifiedHandler.callCount
       runs -> expect(buffer.isModified()).toBe true
 
-    it "reports a modified status of false after a modified buffer is saved", ->
+    it "reports the modified status changing to false after a modified buffer is saved", ->
       filePath = "/tmp/atom-tmp-file"
       fs.write(filePath, '')
       buffer.release()
@@ -225,14 +225,22 @@ describe 'Buffer', ->
       buffer.on 'modified-status-changed', modifiedHandler
 
       buffer.insert([0,0], "hi")
+      advanceClock(buffer.stoppedChangingDelay)
       expect(buffer.isModified()).toBe true
       modifiedHandler.reset()
 
       buffer.save()
+
       expect(modifiedHandler).toHaveBeenCalledWith(false)
       expect(buffer.isModified()).toBe false
+      modifiedHandler.reset()
 
-    it "reports a modified status of false after a modified buffer is reloaded", ->
+      buffer.insert([0, 0], 'x')
+      advanceClock(buffer.stoppedChangingDelay)
+      expect(modifiedHandler).toHaveBeenCalledWith(true)
+      expect(buffer.isModified()).toBe true
+
+    it "reports the modified status changing to false after a modified buffer is reloaded", ->
       filePath = "/tmp/atom-tmp-file"
       fs.write(filePath, '')
       buffer.release()
@@ -241,12 +249,19 @@ describe 'Buffer', ->
       buffer.on 'modified-status-changed', modifiedHandler
 
       buffer.insert([0,0], "hi")
+      advanceClock(buffer.stoppedChangingDelay)
       expect(buffer.isModified()).toBe true
       modifiedHandler.reset()
 
       buffer.reload()
       expect(modifiedHandler).toHaveBeenCalledWith(false)
       expect(buffer.isModified()).toBe false
+      modifiedHandler.reset()
+
+      buffer.insert([0, 0], 'x')
+      advanceClock(buffer.stoppedChangingDelay)
+      expect(modifiedHandler).toHaveBeenCalledWith(true)
+      expect(buffer.isModified()).toBe true
 
     it "returns false for an empty buffer with no path", ->
       buffer.release()

src/app/buffer.coffee

@@ -69,7 +69,7 @@ class Buffer
 
     @file.on "removed", =>
       @updateCachedDiskContents()
-      @trigger "modified-status-changed", @isModified()
+      @triggerModifiedStatusChanged(@isModified())
 
     @file.on "moved", =>
       @trigger "path-changed", this
@@ -78,7 +78,7 @@ class Buffer
     @trigger 'will-reload'
     @updateCachedDiskContents()
     @setText(@cachedDiskContents)
-    @trigger 'modified-status-changed', false
+    @triggerModifiedStatusChanged(false)
     @trigger 'reloaded'
 
   updateCachedDiskContents: ->
@@ -253,7 +253,7 @@ class Buffer
     @setPath(path)
     @cachedDiskContents = @getText()
     @file.write(@getText())
-    @trigger 'modified-status-changed', false
+    @triggerModifiedStatusChanged(false)
     @trigger 'saved'
 
   isModified: ->
@@ -432,11 +432,14 @@ class Buffer
       @stoppedChangingTimeout = null
       modifiedStatus = @isModified()
       @trigger 'contents-modified', modifiedStatus
-      unless modifiedStatus is @previousModifiedStatus
-        @previousModifiedStatus = modifiedStatus
-        @trigger 'modified-status-changed', modifiedStatus
+      @triggerModifiedStatusChanged(modifiedStatus)
     @stoppedChangingTimeout = setTimeout(stoppedChangingCallback, @stoppedChangingDelay)
 
+  triggerModifiedStatusChanged: (modifiedStatus) ->
+    return if modifiedStatus is @previousModifiedStatus
+    @previousModifiedStatus = modifiedStatus
+    @trigger 'modified-status-changed', modifiedStatus
+
   fileExists: ->
     @file.exists()