but you’re referring to Kakoune now as a third-person object. Kakoune doesn’t know any better.
I mean, the Kakoune documentation and source-code use the word “selection” quite consistently that way. In the context of Kakoune and understanding how it works, “selection” has a very specific, technical meaning: a span of adjacent characters.
as a matter of fact, even
a-C don’t do anything when there are newlines or whitespaces either.
C creates a new selection one line below each existing selection, covering the same columns. If the line below is the same length or longer, this is fine and sensible. However, if the line below is shorter, it might not be long enough to have a copy of the selection. Previously, Kakoune would do nothing if you pressed
C and the following line was too short, but these days it skips over too-short lines and adds the selection to the next line that’s long enough.
I still don’t really understand what you’re trying to do. Perhaps you could try describing it in the tradition bug-report format? You know:
- What I tried:
- started Kakoune with
- typed these keys…
- What I expected:
- What actually happened:
For clarity, it’s probably best to follow @andreyorst’s example and use
 to show which parts of the text are selected in your examples, or just post screenshots.