This is something very basic, but annoys me since ever. Using the brush tool (B), I can click at point "A", then shift+click at point "B". A line is drawn from "A" to "B". Simple and effective - I use this a lot to fine-tune layer masks.
If I undo, line is undone, but point "A" is not. Unfortunately, I cannot shift+click "B" again - I got a point at "B" instead of a line.
Am I missing some option to keep the shift+click behavior after undoing?