CommandPanel commands can only be undone if they change the buffer

src/extensions/command-panel/spec/command-interpreter-spec.coffee

@@ -180,6 +180,16 @@ describe "CommandInterpreter", ->
         runs ->
           expect(editSession.getSelectedText()).toBe "y/b"
 
+      it "does not push to the undo stack (since the buffer is not modified)", ->
+        waitsForPromise ->
+          editSession.setSelectedBufferRange([[4,16], [4,20]])
+          interpreter.eval('/pivot/', editSession)
+
+        runs ->
+          selectedRangeBeforeUndo = editSession.getSelection().getBufferRange()
+          editSession.undo()
+          expect(editSession.getSelection().getBufferRange()).toEqual selectedRangeBeforeUndo
+
       describe "when no match is found", ->
         it "it returns an error messages", ->
           errorMessages = null

src/extensions/command-panel/src/commands/composite-command.coffee

@@ -31,7 +31,7 @@ class CompositeCommand
           bufferRanges = []
           errorMessages = @errorMessagesForOperations(operations)
 
-          editSession.transact ->
+          executeOperations = ->
             for operation in operations
               bufferRange = operation.execute(editSession)
               bufferRanges.push(bufferRange) if bufferRange
@@ -40,6 +40,13 @@ class CompositeCommand
               if bufferRanges.length and not currentCommand.preserveSelections
                 editSession.setSelectedBufferRanges(bufferRanges, autoscroll: true)
 
+          operationsWillChangeBuffer = _.detect(operations, (operation) -> operation.newText)
+
+          if operationsWillChangeBuffer
+            editSession.transact(executeOperations)
+          else
+            executeOperations()
+
           deferred.resolve({errorMessages})
 
     deferred.promise()