Placement of code blocks not in undo/redo stack

[andydandy74]

Dynamo version

1.3.1 stable

Operating system

Win 7

What did you do?

• Placed a couple of nodes
• Placed a code block
• Placed some more nodes
• Hit undo several times

What did you expect to see?

The elements disappearing in their order of placements including the empty code block.

What did you see instead?

The elements disappearing in their order of placements except the empty code block.

It appears that code blocks only enter the undo/redo stack once they contain some text (or in other words the event of placing a code block is not recorded). If I place a code block, enter some text into it and then hit undo, the code block disappears (this should be two separate events in the undo/redo stack).

CC @kronz @Racel