patch 8.2.2334: Pascal-like filetypes not always detected

Problem:    Pascal-like filetypes not always detected.
Solution:   Improved Puppet, InstantFPC and Pascal detection. (Doug Kearns,
            closes #7662)

runtime/autoload/dist/ft.vim

@@ -362,6 +362,10 @@ func dist#ft#FTinc()
       setf aspvbs
     elseif lines =~ "<?"
       setf php
+    " Pascal supports // comments but they're vary rarely used for file
+    " headers so assume POV-Ray
+    elseif lines =~ '^\s*\%({\|(\*\)' || lines =~? s:ft_pascal_keywords
+      setf pascal
     else
       call dist#ft#FTasmsyntax()
       if exists("b:asmsyntax")
@@ -408,6 +412,9 @@ func dist#ft#FTprogress_asm()
   setf progress
 endfunc
 
+let s:ft_pascal_comments = '^\s*\%({\|(\*\|//\)'
+let s:ft_pascal_keywords = '^\s*\%(program\|unit\|library\|uses\|begin\|procedure\|function\|const\|type\|var\)\>'
+
 func dist#ft#FTprogress_pascal()
   if exists("g:filetype_p")
     exe "setf " . g:filetype_p
@@ -419,8 +426,7 @@ func dist#ft#FTprogress_pascal()
   let lnum = 1
   while lnum <= 10 && lnum < line('$')
     let line = getline(lnum)
-    if line =~ '^\s*\(program\|unit\|procedure\|function\|const\|type\|var\)\>'
-	\ || line =~ '^\s*{' || line =~ '^\s*(\*'
+    if line =~ s:ft_pascal_comments || line =~? s:ft_pascal_keywords
       setf pascal
       return
     elseif line !~ '^\s*$' || line =~ '^/\*'
@@ -433,6 +439,19 @@ func dist#ft#FTprogress_pascal()
   setf progress
 endfunc
 
+func dist#ft#FTpp()
+  if exists("g:filetype_pp")
+    exe "setf " . g:filetype_pp
+  else
+    let line = getline(nextnonblank(1))
+    if line =~ s:ft_pascal_comments || line =~? s:ft_pascal_keywords
+      setf pascal
+    else
+      setf puppet
+    endif
+  endif
+endfunc
+
 func dist#ft#FTr()
   let max = line("$") > 50 ? 50 : line("$")
 

runtime/filetype.vim

@@ -1174,7 +1174,9 @@ au BufNewFile,BufRead *.papp,*.pxml,*.pxsl	setf papp
 au BufNewFile,BufRead */etc/passwd,*/etc/passwd-,*/etc/passwd.edit,*/etc/shadow,*/etc/shadow-,*/etc/shadow.edit,*/var/backups/passwd.bak,*/var/backups/shadow.bak setf passwd
 
 " Pascal (also *.p)
-au BufNewFile,BufRead *.pas,*.pp		setf pascal
+au BufNewFile,BufRead *.pas			setf pascal
+
+au BufNewFile,BufRead *.pp			call dist#ft#FTpp()
 
 " Delphi or Lazarus program file
 au BufNewFile,BufRead *.dpr,*.lpr		setf pascal

runtime/scripts.vim

@@ -182,6 +182,10 @@ if s:line1 =~# "^#!"
   elseif s:name =~# 'clojure'
     set ft=clojure
 
+    " Free Pascal
+  elseif s:name =~# 'instantfpc\>'
+    set ft=pascal
+
   endif
   unlet s:name