vim-patch:9.1.0386: filetype: stylus files not recognized

Problem:  filetype: stylus files not recognized
Solution: Detect '*.styl' and '*.stylus' as stylus filetype,
          include indent, filetype and syntax plugin
          (Philip H)

closes: vim/vim#14656

2d919d2744

Co-authored-by: Philip H <47042125+pheiduck@users.noreply.github.com>

runtime/indent/stylus.vim

@@ -0,0 +1,121 @@
+" Vim indent file
+" Language: Stylus
+" Maintainer: Marc Harter
+" Last Change: 2010 May 21
+" Based On: sass.vim from Tim Pope
+"
+if exists("b:did_indent")
+  finish
+endif
+let b:did_indent = 1
+
+setlocal indentexpr=GetStylusIndent()
+setlocal indentkeys=o,O,*<Return>,},],0),!^F
+let b:undo_indent = "setl indentexpr< indentkeys<"
+
+if exists("*GetStylusIndent")  " only define once
+  finish
+endif
+
+function s:prevnonblanknoncomment(lnum)
+  let lnum = a:lnum
+  while lnum > 1
+    let lnum = prevnonblank(lnum)
+    let line = getline(lnum)
+    if line =~ '\*/'
+      while lnum > 1 && line !~ '/\*'
+        let lnum -= 1
+      endwhile
+      if line =~ '^\s*/\*'
+        let lnum -= 1
+      else
+        break
+      endif
+    else
+      break
+    endif
+  endwhile
+  return lnum
+endfunction
+
+function s:count_braces(lnum, count_open)
+  let n_open = 0
+  let n_close = 0
+  let line = getline(a:lnum)
+  let pattern = '[{}]'
+  let i = match(line, pattern)
+  while i != -1
+    if synIDattr(synID(a:lnum, i + 1, 0), 'name') !~ 'css\%(Comment\|StringQ\{1,2}\)'
+      if line[i] == '{'
+        let n_open += 1
+      elseif line[i] == '}'
+        if n_open > 0
+          let n_open -= 1
+        else
+          let n_close += 1
+        endif
+      endif
+    endif
+    let i = match(line, pattern, i + 1)
+  endwhile
+  return a:count_open ? n_open : n_close
+endfunction
+
+" function CheckCSSIndent()
+"   let line = getline(v:lnum)
+"   if line =~ '^\s*\*'
+"     return cindent(v:lnum)
+"   endif
+" 
+"   let pnum = s:prevnonblanknoncomment(v:lnum - 1)
+"   if pnum == 0
+"     return 0
+"   endif
+
+function! GetStylusIndent()
+  let line = getline(v:lnum)
+  if line =~ '^\s*\*'
+    return cindent(v:lnum)
+  endif
+
+  let pnum = s:prevnonblanknoncomment(v:lnum - 1)
+  if pnum == 0
+    return 0
+  endif
+
+  let lnum     = prevnonblank(v:lnum-1)
+  if lnum == 0
+    return 0
+  endif
+
+  let pline = getline(pnum)
+
+  if pline =~ '[}{]'
+    return indent(pnum) + s:count_braces(pnum, 1) * &sw - s:count_braces(v:lnum, 0) * &sw
+  endif
+
+  let line     = substitute(getline(lnum),'[\s()]\+$','','')  " get last line strip ending whitespace
+  let cline    = substitute(substitute(getline(v:lnum),'\s\+$','',''),'^\s\+','','')  " get current line, trimmed
+  let lastcol  = strlen(line)  " get last col in prev line
+  let line     = substitute(line,'^\s\+','','')  " then remove preceeding whitespace
+  let indent   = indent(lnum)  " get indent on prev line
+  let cindent  = indent(v:lnum)  " get indent on current line
+  let increase = indent + &sw  " increase indent by the shift width
+  if indent   == indent(lnum)
+    let indent = cindent <= indent ? indent : increase
+  endif
+
+  let group = synIDattr(synID(lnum,lastcol,1),'name')
+
+  " if group !~? 'css.*' && line =~? ')\s*$' " match user functions
+  "   return increase
+  if group =~? '\v^%(cssTagName|cssClassName|cssIdentifier|cssSelectorOp|cssSelectorOp2|cssBraces|cssAttributeSelector|cssPseudo|stylusId|stylusClass)$'
+    return increase
+  elseif (group == 'stylusUserFunction') && (indent(lnum) == '0') " mixin definition
+    return increase
+  else
+    return indent
+  endif
+endfunction
+
+" vim:set sw=2;