nvim: fugitive: Add mapping to view file on another branch

nvim/.config/nvim/after/plugin/fugitive.vim

@@ -36,6 +36,7 @@ nnoremap <Leader>G  :keepalt Git<SPACE>
 
 nnoremap <Leader>gp :call git#git_push_to_upstream()<CR>
 nnoremap <expr> <Leader>gP git#git_push()
+nnoremap <expr> <Leader>gO git#git_show_file_on_branch()
 
 augroup custom_fugitive
   autocmd!

nvim/.config/nvim/autoload/git.vim

@@ -289,6 +289,11 @@ function! git#git_review_fileview() abort
   execute "Git difftool -y " . default[3] . "..." . current
 endfunction
 
+" Show file on another branch without changing current branch
+function! git#git_show_file_on_branch() abort
+  return ":Git show :" . expand("%")
+endfunction
+
 " Generate a helpful name when using Git stash
 function! git#git_stash() abort
   let current = trim(system("git branch --show-current"))