One-step undo in TextInput

[Alspb]

Feature request
When I select text in TextInput and press Paste, new text is inserted instead of the selected one. But in fact this action consists of two steps: 1) delete selection, 2) insert text.
So if I press Undo, inserted text disappears, but the initially selected text still remain deleted. So I need to press Undo twice to get the initial text.
It would be great to press Undo only once to get back to the initial text.

Why it is important:

• Most of (text) editors behave this way (the only exception I've found is Python's IDLE)
• Text disappearance after first Undo may confuse the user
• It's convenient for implementing new text format/edit features. E.g. "increase indent" function could be implemented by deleting old paragraph and inserting the new, indented, one. But currently this approach is unhandy, cause the user won't see his paragraph after the first Undo.