Using CTRL+Z to undo text writes will override the last known line position when making newlines

[system2k]

Quote from itac85v2:

So if I type "abc" and press enter, I'll start one line below the "a" (as expected).
Then, if I were to type "abcdefg" and undo the "fg", pressing enter will leave me one line where the "f" originally was, and not beneath the "a".

Further bug report which may be related:

the very top row on the paste preview is sometimes shifted right by 1 cell. clicking to paste will also have this issue.
can't find how to reproduce, it just happens sometimes
pressing esc and redoing the paste preview will almost always fix it

[SillySylveon]

After looking into the code, this seems to be less of a bug and more of an enhancement. Currently, the client will override verticalEnterPos to whatever X coordinate that the character that was undone is located at, caused by a call to moveCursor() in the undoWrite function. This works fine in most cases, but in some cases this is a bit of an annoying behavior.

A proposed fix to this would be:

• When undoing, first check what coordinates the character to undo is located at, and what coordinates the cursor is currently located in
• If:
  • the undone character is currently visible on-screen,
  • AND the undone character's X coordinate is not less than the value of verticalEnterPos,
• then we do not override the value of verticalEnterPos.
• If at least one of these conditions aren't met, it should still override the saved verticalEnterPos value.