Fix cancelling insert mode (#546)

* Fix cancelling insert mode

* Revert "get proper window number (#541)"

This reverts commit 59daf85.

Author: thomasfaingnaert

autoload/lsp/ui/vim/folding.vim

@@ -178,10 +178,15 @@ function! s:handle_fold_request(server, data) abort
     endif
     let s:folding_ranges[a:server][l:bufnr] = l:result
 
+    " Don't do the 'windo' in Insert mode, it puts Vim back in Normal mode.
+    if mode()[0] ==# 'i'
+        return
+    endif
+
     " Set 'foldmethod' back to 'expr', which forces a re-evaluation of
     " 'foldexpr'. Only do this if the user hasn't changed 'foldmethod',
     " and this is the correct buffer.
-    let l:current_window = bufwinnr()
+    let l:current_window = winnr()
     windo if &l:foldmethod ==# 'expr' && bufnr('%') == l:bufnr | let &l:foldmethod = 'expr' | endif
     execute l:current_window . 'wincmd w'
 endfunction