If you are seeing a similar issue and using Windows Terminal jump down to the "Update" below.
<ESC> used as the LHS of a key mapping causes me some discomfort. You've demonstrated one reason why...it doesn't seem to work right in a vimrc file. It doesn't matter what you have on the RHS, the LHS
<ESC> causes some characters (maybe related to the underlying key code for
<ESC>) to be emitted as if they were Normal mode commands and those include
2R. (If you type something right after entring Vim and hit escape you'll see the typed string replace current text twice.)
My first bit of advice would be to save the headaches and use a different key for mapping. If you really want to use
<ESC> then continue...
My first instinct while trying to fix things was to use an
autocommand to delay the setup of the mapping but that doesn't help. It's still in the context that doesn't play nice with LHS
My second notion was to also use an
autocommand but with an asynchronous call since these involve a thread that is separate from the mainline of execution and likely a totally different context than is used to process vimrc files. Turns out, it works...
nnoremap <ESC> :nohlsearch<CR><ESC>
autocmd VimEnter * call timer_start(100, 'EscMapSetup')
Has that hack smell to it but if someone can't come up with the root cause of this issue and a clean way around it this isn't too bad...at least it doesn't require any particular timing. I chose 100ms above arbitrarily and because its short.
What is the purpose of the
<ESC> on the RHS of the mapping? You're already in Normal mode so it doesn't do anything there. Only thing I can think of is you want to clear the command line of the
nohlsearch text that lingers there. If so, consider using
<C-L> in it's place. That will redraw the screen after cleaning it...that leaves a pristine c/l...and no more flirting with problems that the special status of
<ESC> sometimes bears.
2020-12-05 Update: Per the numerous comments below Command already typed in when I open vim there is a bug, since fixed and released in September, in the Windows Terminal terminal emulator.
You can either get the latest version of WT or you can try an alternate terminal emulator. I personally use and like mintty.
There is also a workaround that appears to be benign:
In short the problem is how WT handles the control sequence contained in
't_u7'. This control sequence, valid only for xterm-compatible terminal emulators, is used to get the cursor's position. Vim sends the sequence to the terminal on startup under certain conditions (i.e. if using utf-8
'encoding' or similar) to find out how wide characters are represented. When WT responds it mixes the answer with the response to a separate control sequence such that individual characters are intermingled rendering the whole thing invalid and causing Vim to think it's normal user input. It so happens that the last two characters are usually
2R which explains why things behave as if you entered that Normal mode command.