nvim: plugins: Drop diffview

Something as basic as :DiffviewOpen <commit> does not work.

nvim/.config/nvim/after/ftplugin/git.vim

@@ -4,8 +4,7 @@ nnoremap <buffer> <Leader>gb :call git#git_branch_checkout()<CR>
 nnoremap <buffer> <Leader>gB :call git#git_branch_delete()<CR>
 nnoremap <buffer> <Leader>gc :call git#git_cherry_pick()<CR>
 xnoremap <buffer> <Leader>gC :<C-U>call git#git_cherry_pick_range()<CR>
-nnoremap <buffer> <Leader>gd :call git#git_diffview_commit()<CR>
-nnoremap <buffer> <Leader>gD :call git#git_diff_commit()<CR>
+nnoremap <buffer> <Leader>gd :call git#git_diff_commit()<CR>
 nnoremap <buffer> <Leader>gl :call git#git_branch_log()<CR>
 nnoremap <buffer> <Leader>gL :call git#git_branch_log_pretty()<CR>
 nnoremap <buffer> <Leader>gr :call git#git_rebase_branch()<CR>

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

@@ -110,15 +110,6 @@ function! git#git_diff_commit() abort
   silent execute "Git difftool -y " . commit[1] . "^!"
 endfunction
 
-" Run DiffviewOpen on the commit in the line which we are at. To be used after
-" running some variation of Git log.
-function! git#git_diffview_commit() abort
-  " A line in Git log is of the form commit <SHA>
-  let line = trim(getline('.'))
-  let commit = split(line, " ")
-  silent execute "DiffviewOpen " . commit[1] . "^!"
-endfunction
-
 " The next two functions allow scoping diffs by line range of a file and named
 " block in a file. Inspired by reading the following article.
 " https://susanpotter.net/software/tracking-diffs-by-scoping-to-file-range-function-method-or-class-changes-in-git/

nvim/.config/nvim/lua/plugins.lua

@@ -35,7 +35,6 @@ local init = function ()
   use 'tpope/vim-fugitive'
   use 'rhysd/git-messenger.vim'
   use 'whiteinge/diffconflicts'
-  use 'sindrets/diffview.nvim'
   -- Boost vim command line mode
   use 'vim-utils/vim-husk'
   -- Quickfix