Make Buffer.transact restore marker ranges on undo/redo of transaction

We no longer need to restore selection ranges before and after
transactions now because selections are based on markers so they go
along for the ride for free. This allows us to delegate directly to
Buffer.transact from EditSession.

src/app/buffer-change-operation.coffee

@@ -21,14 +21,15 @@ class BufferChangeOperation
   do: ->
     @buffer.pauseEvents()
     @pauseMarkerObservation()
-    @oldText = @buffer.getTextInRange(@oldRange)
-    @newRange = @calculateNewRange(@oldRange, @newText)
     @markersToRestoreOnUndo = @invalidateMarkers(@oldRange)
-    newRange = @changeBuffer
-      oldRange: @oldRange
-      newRange: @newRange
-      oldText: @oldText
-      newText: @newText
+    if @oldRange?
+      @oldText = @buffer.getTextInRange(@oldRange)
+      @newRange = @calculateNewRange(@oldRange, @newText)
+      newRange = @changeBuffer
+        oldRange: @oldRange
+        newRange: @newRange
+        oldText: @oldText
+        newText: @newText
     @restoreMarkers(@markersToRestoreOnRedo) if @markersToRestoreOnRedo
     @buffer.resumeEvents()
     @resumeMarkerObservation()
@@ -38,11 +39,12 @@ class BufferChangeOperation
     @buffer.pauseEvents()
     @pauseMarkerObservation()
     @markersToRestoreOnRedo = @invalidateMarkers(@newRange)
-    @changeBuffer
-      oldRange: @newRange
-      newRange: @oldRange
-      oldText: @newText
-      newText: @oldText
+    if @oldRange?
+      @changeBuffer
+        oldRange: @newRange
+        newRange: @oldRange
+        oldText: @newText
+        newText: @oldText
     @restoreMarkers(@markersToRestoreOnUndo)
     @buffer.resumeEvents()
     @resumeMarkerObservation()
@@ -107,7 +109,7 @@ class BufferChangeOperation
 
   resumeMarkerObservation: ->
     marker.resumeEvents() for marker in @buffer.getMarkers(includeInvalid: true)
-    @buffer.trigger 'markers-updated'
+    @buffer.trigger 'markers-updated' if @oldRange?
 
   updateMarkers: (bufferChange) ->
     marker.handleBufferChange(bufferChange) for marker in @buffer.getMarkers()

src/app/buffer-marker.coffee

@@ -179,23 +179,24 @@ class BufferMarker
   ###
 
   tryToInvalidate: (changedRange) ->
-    betweenStartAndEnd = @getRange().containsRange(changedRange, exclusive: false)
-    containsStart = changedRange.containsPoint(@getStartPosition(), exclusive: true)
-    containsEnd = changedRange.containsPoint(@getEndPosition(), exclusive: true)
     previousRange = @getRange()
-    switch @invalidationStrategy
-      when 'between'
-        @invalidate() if betweenStartAndEnd or containsStart or containsEnd
-      when 'contains'
-        @invalidate() if containsStart or containsEnd
-      when 'never'
-        if containsStart or containsEnd
-          if containsStart and containsEnd
-            @setRange([changedRange.end, changedRange.end])
-          else if containsStart
-            @setRange([changedRange.end, @getEndPosition()])
-          else
-            @setRange([@getStartPosition(), changedRange.start])
+    if changedRange
+      betweenStartAndEnd = @getRange().containsRange(changedRange, exclusive: false)
+      containsStart = changedRange.containsPoint(@getStartPosition(), exclusive: true)
+      containsEnd = changedRange.containsPoint(@getEndPosition(), exclusive: true)
+      switch @invalidationStrategy
+        when 'between'
+          @invalidate() if betweenStartAndEnd or containsStart or containsEnd
+        when 'contains'
+          @invalidate() if containsStart or containsEnd
+        when 'never'
+          if containsStart or containsEnd
+            if containsStart and containsEnd
+              @setRange([changedRange.end, changedRange.end])
+            else if containsStart
+              @setRange([changedRange.end, @getEndPosition()])
+            else
+              @setRange([@getStartPosition(), changedRange.start])
     [@id, previousRange]
 
   handleBufferChange: (bufferChange) ->

src/app/edit-session.coffee

@@ -618,26 +618,11 @@ class EditSession
   # Internal #
   ###
 
-  transact: (fn) ->
-    isNewTransaction = @buffer.transact()
-    oldSelectedRanges = @getSelectedBufferRanges()
-    @pushOperation
-      undo: (editSession) ->
-        editSession?.setSelectedBufferRanges(oldSelectedRanges, preserveFolds: true)
-    if fn
-      result = fn()
-      @commit() if isNewTransaction
-      result
+  transact: (fn) -> @buffer.transact(fn)
 
-  commit: ->
-    newSelectedRanges = @getSelectedBufferRanges()
-    @pushOperation
-      redo: (editSession) ->
-        editSession?.setSelectedBufferRanges(newSelectedRanges, preserveFolds: true)
-    @buffer.commit()
+  commit: -> @buffer.commit()
 
-  abort: ->
-    @buffer.abort()
+  abort: -> @buffer.abort()
 
   ###
   # Public #

src/app/text-buffer.coffee

@@ -376,17 +376,30 @@ class Buffer
       operation.do()
 
   # Internal:
-  transact: (fn) ->  @undoManager.transact(fn)
+  transact: (fn) ->
+    if isNewTransaction = @undoManager.transact()
+      @pushOperation(new BufferChangeOperation(buffer: this)) # restores markers on undo
+    if fn
+      try
+        fn()
+      finally
+        @commit() if isNewTransaction
+
+  commit: ->
+    @pushOperation(new BufferChangeOperation(buffer: this)) # restores markers on redo
+    @undoManager.commit()
+
+  abort: -> @undoManager.abort()
+
   # Public: Undos the last operation.
   #
   # editSession - The {EditSession} associated with the buffer.
   undo: (editSession) -> @undoManager.undo(editSession)
+
   # Public: Redos the last operation.
   #
   # editSession - The {EditSession} associated with the buffer.
   redo: (editSession) -> @undoManager.redo(editSession)
-  commit: -> @undoManager.commit()
-  abort: -> @undoManager.abort()
 
   # Public: Saves the buffer.
   save: ->

src/app/undo-manager.coffee

@@ -31,11 +31,6 @@ class UndoManager
   transact: (fn) ->
     isNewTransaction = not @currentTransaction?
     @currentTransaction ?= []
-    if fn
-      try
-        fn()
-      finally
-        @commit() if isNewTransaction
     isNewTransaction
 
   commit: ->
@@ -61,7 +56,6 @@ class UndoManager
         opsInReverse = new Array(batch...)
         opsInReverse.reverse()
         op.undo?(editSession) for op in opsInReverse
-
         @redoHistory.push batch
         batch.oldSelectionRanges
     catch e