In my Vim configuration, I have mapped the <C-j> key to <cmd>bn<CR>, but because the C-j key corresponds to the null character in Vim, this causes some strange issues when defining macros. For instance, if I define a macro for q with
qq<CR>q
the macro executes the keystroke <CR>, as expected. But if I try to define @q directly with the keystrokes,
:let @q='^M'<CR>
where ^M is the literal newline character, executing q with @q behaves like <CR><C-j>. And indeed, checking :reg shows that "q=^M^J when defined directly, and "q=^M when defined via macro recording. It seems like this extra null character is only appended when the string ends in a carriage return.
I would like to be able to define "q directly without this terminating null character. My solution for now has been to replace ^M$ with ^M^[. While this works for virtually all cases, it's not perfect (for instance, if the macro ends in the middle of a chord, the <nop> would exit the chord).
Why does assignment and macro recording differ in this way? And is there a way to perform assign a register without this terminating null character?
