Undo undoes multiple actions, most notably repeat history (".")

[arthaud]

Hello,

First of all, thanks for making this, this is a lifesaver! The fact that all keyboard actions are simple dance commands made it easy to recreate my weird helix configuration.

I have a bug with "undo" (u) when using repeat history ("."). It undoes more than a single action.

For instance, assume we start with a file containing:

A
B
C

Then, place your cursor on A, go into insert mode, add X and a space, then go back to normal mode:

X A
B
C

Go to the second line, on B, and press the repeat-history (usually mapped to dot ".")

X A
X B
C

Do the same on the next line. Go to C and press repeat-history

X A
X B
X C

Now, if you press undo (u), this will remove the X on C, but also on B. It "undoes" the two previous actions.
Current result:

XA
B
C

Expected: (only undo the last action)

X A
X B
C

(it's even slightly worse, as it also removes the space between X and A. not sure why)

I would love to have this fixed, as it is quite annoying. I use repeat-history quite often.
If I get the time, I might look into this, so I would appreciate pointers if no one else wants to fix it. Is there a way to force the repeat-history to "record" an action? Or does this need a whole rework of the history logic handling?

Thanks.