vim-patch:9.1.0354: runtime(uci): No support for uci file types (#28409)

Problem:  runtime(uci): No support for uci file types
          (Wu, Zhenyu)
Solution: include basic uci ftplugin and syntax plugins
          (Colin Caine)

closes: vim/vim#14575

4b3fab14db

Co-authored-by: Colin Caine <complaints@cmcaine.co.uk>
Co-authored-by: Wu, Zhenyu <wuzhenyu@ustc.edu>

runtime/lua/vim/filetype.lua

@@ -14,7 +14,8 @@ local M = {}
 local function starsetf(ft, opts)
   return {
     function(path, bufnr)
-      local f = type(ft) == 'function' and ft(path, bufnr) or ft
+      -- Note: when `ft` is a function its return value may be nil.
+      local f = type(ft) ~= 'function' and ft or ft(path, bufnr)
       if not vim.g.ft_ignore_pat then
         return f
       end
@@ -2138,6 +2139,7 @@ local pattern = {
   ['.*/%.init/.*%.conf'] = 'upstart',
   ['.*/usr/share/upstart/.*%.override'] = 'upstart',
   ['.*%.[Ll][Oo][Gg]'] = detect.log,
+  ['.*/etc/config/.*'] = starsetf(detect.uci),
   ['.*%.vhdl_[0-9].*'] = starsetf('vhdl'),
   ['.*%.ws[fc]'] = 'wsh',
   ['.*/Xresources/.*'] = starsetf('xdefaults'),

runtime/lua/vim/filetype/detect.lua

@@ -1584,6 +1584,26 @@ function M.typ(_, bufnr)
   return 'typst'
 end
 
+--- @type vim.filetype.mapfn
+function M.uci(_, bufnr)
+  -- Return "uci" iff the file has a config or package statement near the
+  -- top of the file and all preceding lines were comments or blank.
+  for _, line in ipairs(getlines(bufnr, 1, 3)) do
+    -- Match a config or package statement at the start of the line.
+    if
+      line:find('^%s*[cp]%s+%S')
+      or line:find('^%s*config%s+%S')
+      or line:find('^%s*package%s+%S')
+    then
+      return 'uci'
+    end
+    -- Match a line that is either all blank or blank followed by a comment
+    if not (line:find('^%s*$') or line:find('^%s*#')) then
+      break
+    end
+  end
+end
+
 -- Determine if a .v file is Verilog, V, or Coq
 --- @type vim.filetype.mapfn
 function M.v(_, bufnr)