Restore selections after undo

This only restores changes made via the CompositeSelection… this makes sense because this is the only way to make changes interactively. Any other changes are made via the api or a command line and should not modify selections when they are undone. Still need to test restoration after redo.

src/app/buffer.coffee

@@ -127,11 +127,11 @@ class Buffer
     @lines[oldRange.start.row..oldRange.end.row] = newTextLines
     @trigger 'change', { oldRange, newRange, oldText, newText }
 
-  startUndoBatch: ->
-    @undoManager.startUndoBatch()
+  startUndoBatch: (selectedBufferRanges) ->
+    @undoManager.startUndoBatch(selectedBufferRanges)
 
-  endUndoBatch: ->
-    @undoManager.endUndoBatch()
+  endUndoBatch: (selectedBufferRanges) ->
+    @undoManager.endUndoBatch(selectedBufferRanges)
 
   undo: ->
     @undoManager.undo()

src/app/composite-selection.coffee

@@ -16,6 +16,9 @@ class CompositeSeleciton
   getSelections: ->
     new Array(@selections...)
 
+  getSelectedBufferRanges: ->
+    selection.getBufferRange() for selection in @getSelections()
+
   getLastSelection: ->
     _.last(@selections)
 
@@ -57,10 +60,12 @@ class CompositeSeleciton
     @getLastSelection().setBufferRange(bufferRange, options)
 
   setBufferRanges: (bufferRanges) ->
-    @clearSelections()
-    @setBufferRange(bufferRanges[0])
-    for bufferRange in bufferRanges[1..]
-      @addSelectionForBufferRange(bufferRange)
+    selections = @getSelections()
+    for bufferRange, i in bufferRanges
+      if selections[i]
+        selections[i].setBufferRange(bufferRange)
+      else
+        @addSelectionForBufferRange(bufferRange)
     @mergeIntersectingSelections()
 
   getBufferRange: (bufferRange) ->
@@ -79,12 +84,9 @@ class CompositeSeleciton
 
   mutateSelectedText: (fn) ->
     selections = @getSelections()
-    if selections.length > 1
-      @editor.buffer.startUndoBatch()
-      fn(selection) for selection in selections
-      @editor.buffer.endUndoBatch()
-    else
-      fn(selections[0])
+    @editor.buffer.startUndoBatch(@getSelectedBufferRanges())
+    fn(selection) for selection in selections
+    @editor.buffer.endUndoBatch()
 
   insertText: (text) ->
     @mutateSelectedText (selection) -> selection.insertText(text)

src/app/editor.coffee

@@ -428,7 +428,8 @@ class Editor extends View
   foldSelection: -> @getSelection().fold()
 
   undo: ->
-    @buffer.undo()
+    if ranges = @buffer.undo()
+      @setSelectedBufferRanges(ranges)
 
   redo: ->
     @buffer.redo()