[nvim] fix Polyglot's bundled vim-sleuth (plus a couple of minor edits)

And remove detectindent because now I no longer need it.

nvim/coc-languages/python.vim

@@ -5,11 +5,11 @@ let g:coc_filetypes += ['python']
 let g:coc_user_config['python'] = {
 \ 'formatting': {
 \   'provider': 'yapf',
-\   'yapfArgs': ['--style=' . simplify(g:nvim_dotfiles_dir.'/../python/yapf.ini')]
+\   'yapfArgs': ['--style=' . simplify(g:dotfiles_dir.'/python/yapf.ini')]
 \   },
 \ 'linting': {
 \   'pylintEnabled': v:false,
 \   'flake8Enabled': v:true,
-\   'flake8Args': ['--config=' . simplify(g:nvim_dotfiles_dir.'/../python/flake8.ini')],
+\   'flake8Args': ['--config=' . simplify(g:dotfiles_dir.'/python/flake8.ini')],
 \   },
 \ }

nvim/colors/dotfiles.vim

@@ -3,12 +3,14 @@
 
 " Color definitions {{{
 
-  execute 'source' fnameescape(g:nvim_dotfiles_dir.'/../colorschemes/out/vim.vim')
+  execute 'source' fnameescape(g:dotfiles_dir.'/colorschemes/out/vim.vim')
 
   if !&termguicolors && exists('$_COLORSCHEME_TERMINAL')
     set notermguicolors
   endif
 
+  let s:is_kitty = $TERM ==# 'xterm-kitty'
+
 " }}}
 
 " Theme setup {{{
@@ -139,7 +141,6 @@
   hi! link ctrlsfMatch     Search
   hi! link ctrlsfLnumMatch ctrlsfMatch
 
-  let s:is_kitty = $TERM ==# 'xterm-kitty'
   let s:spell_fg   = s:is_kitty ? ''          : 'bg'
   let s:spell_bg   = s:is_kitty ? 'NONE'      : ''
   let s:spell_attr = s:is_kitty ? 'undercurl' : ''

nvim/dotfiles/plugins-list.vim

@@ -15,7 +15,6 @@
   Plug 'tomtom/tcomment_vim'
   Plug 'tpope/vim-surround'
   Plug 'Yggdroot/indentLine'
-  Plug 'idbrii/detectindent'
   Plug 'henrik/vim-indexed-search'
   Plug 'andymass/vim-matchup'
   Plug 'inkarkat/vim-ingo-library'  " required by LineJuggler

nvim/init.vim

@@ -1,4 +1,5 @@
 let g:nvim_dotfiles_dir = expand('<sfile>:p:h')
+let g:dotfiles_dir = expand('<sfile>:p:h:h')
 
 let g:vim_ide = get(g:, 'vim_ide', 0)
 let g:vim_ide_treesitter = get(g:, 'vim_ide_treesitter', 0)
@@ -16,6 +17,21 @@ if !filereadable(s:vim_plug_script)
   autocmd VimEnter * PlugInstall --sync
 endif
 
+" HACK: Set `shiftwidth` to something unreasonable to make Polyglot's built-in
+" indentation detector believe that it's the "default" value. The problem
+" comes from the fact that Polyglot bundles vim-sleuth, but executes it in an
+" autoload script, which is loaded by an ftdetect script, which is... loaded
+" when vim-plug invokes `filetype on`. Thus vim-sleuth is loaded way before
+" the primary chunk of my configuration is loaded, so it won't see my
+" preferred indentation value, save 8 (Vim's default) to a local variable
+" `s:default_shiftwidth` and always assume that some ftplugin explicitly
+" modified the shiftwidth to 2 (my real default value) for that particular
+" filetype. So instead I use a classic approach to rectify the problem:
+" ridiculously hacky workarounds. In any case, blame this commit:
+" <https://github.com/sheerun/vim-polyglot/commit/113f9b8949643f7e02c29051ad2148c3265b8131>.
+let s:fake_default_shiftwidth = 0
+let &shiftwidth = s:fake_default_shiftwidth
+
 call plug#begin(s:vim_plug_home)
 Plug 'junegunn/vim-plug'
 runtime! dotfiles/plugins-list.vim
@@ -35,3 +51,27 @@ endif
 " }}}
 
 colorscheme dotfiles
+
+if exists(':Sleuth')
+  " HACK: Continuation of the indentation detection hack. Here I first destroy
+  " Polyglot's vim-sleuth's autocommands, fortunately there is just one, which
+  " calls `s:detect_indent()` on `BufEnter`. And also registration into tpope's
+  " statusline plugin, which I don't use, therefore I don't care.
+  augroup polyglot-sleuth
+    autocmd!
+    " HACK: Now I install my own autocommand, which first resets the local
+    " shiftwidth to the unreasonable value picked above, which vim-sleuth
+    " internally compares with its local `s:default_shiftwidth`, sees that both
+    " are the same, and proceeds to execute the indent detection algorithm.
+    " Boom, my work here is done.
+    autocmd BufEnter * let &l:shiftwidth = s:fake_default_shiftwidth | Sleuth
+  augroup END
+
+  " HACK: In case you are wondering why I'm using Polyglot's bundled vim-sleuth
+  " given that it requires those terrible hacks to function normally and respect
+  " my configs, and not something like <https://github.com/idbrii/detectindent>
+  " (this is a fork I used to use and which checks syntax groups to improve
+  " detection quality). ...Well, frankly, even though vim-sleuth's detector uses
+  " unreliable (at first glance) regex heuristics, in practice it still works
+  " better than detectindent's syntax group querying.
+endif

nvim/plugin/editing.vim

@@ -38,21 +38,6 @@ set commentstring=//%s
     autocmd VimEnter * if bufname('%') == '' | IndentLinesDisable | endif
   augroup END
 
-  let g:detectindent_max_lines_to_analyse = 128
-  let g:detectindent_check_comment_syntax = 1
-
-  function s:DetectIndent()
-    if !empty(&bt) | return | endif
-    let g:detectindent_preferred_indent = &l:shiftwidth
-    let g:detectindent_preferred_expandtab = &l:expandtab
-    DetectIndent
-  endfunction
-
-  augroup vimrc-detect-indent
-    autocmd!
-    autocmd BufReadPost * call s:DetectIndent()
-  augroup END
-
 " }}}