patch 8.2.3686: filetype detection often mixes up Forth and F#

Problem:    Filetype detection often mixes up Forth and F#.
Solution:   Add a function to inspect the file contents. (Doug Kearns)

runtime/autoload/dist/ft.vim

@@ -219,6 +219,23 @@ func dist#ft#FTe()
   endif
 endfunc
 
+" Distinguish between Forth and F#.
+" Provided by Doug Kearns.
+func dist#ft#FTfs()
+  if exists("g:filetype_fs")
+    exe "setf " . g:filetype_fs
+  else
+    let line = getline(nextnonblank(1))
+    " comments and colon definitions
+    if line =~ '^\s*\.\=( ' || line =~ '^\s*\\G\= ' || line =~ '^\\$'
+	  \ || line =~ '^\s*: \S'
+      setf forth
+    else
+      setf fs
+    endif
+  endif
+endfunc
+
 " Distinguish between HTML, XHTML and Django
 func dist#ft#FThtml()
   let n = 1

runtime/doc/filetype.txt

@@ -139,18 +139,19 @@ can be used to overrule the filetype used for certain extensions:
 
 	file name	variable ~
 	*.asa		g:filetype_asa	|ft-aspvbs-syntax| |ft-aspperl-syntax|
-	*.asp		g:filetype_asp	|ft-aspvbs-syntax| |ft-aspperl-syntax|
 	*.asm		g:asmsyntax	|ft-asm-syntax|
-	*.prg		g:filetype_prg
-	*.pl		g:filetype_pl
-	*.inc		g:filetype_inc
-	*.w		g:filetype_w	|ft-cweb-syntax|
+	*.asp		g:filetype_asp	|ft-aspvbs-syntax| |ft-aspperl-syntax|
+	*.fs		g:filetype_fs   |ft-forth-syntax|
 	*.i		g:filetype_i	|ft-progress-syntax|
+	*.inc		g:filetype_inc
 	*.m		g:filetype_m	|ft-mathematica-syntax|
 	*.p		g:filetype_p	|ft-pascal-syntax|
+	*.pl		g:filetype_pl
 	*.pp		g:filetype_pp	|ft-pascal-syntax|
+	*.prg		g:filetype_prg
 	*.sh		g:bash_is_sh	|ft-sh-syntax|
 	*.tex		g:tex_flavor	|ft-tex-plugin|
+	*.w		g:filetype_w	|ft-cweb-syntax|
 
 							*filetype-ignore*
 To avoid that certain files are being inspected, the g:ft_ignore_pat variable
@@ -538,6 +539,14 @@ Options:
 For further discussion of fortran_have_tabs and the method used for the
 detection of source format see |ft-fortran-syntax|.
 
+GPROF							*ft-gprof-plugin*
+
+The gprof filetype plugin defines a mapping <C-]> to jump from a function
+entry in the gprof flat profile or from a function entry in the call graph
+to the details of that function in the call graph.
+
+The mapping can be disabled with: >
+	let g:no_gprof_maps = 1
 
 GIT COMMIT                                              *ft-gitcommit-plugin*
 

runtime/doc/syntax.txt

@@ -1533,6 +1533,14 @@ gvim display.  Here, statements are colored LightYellow instead of Yellow, and
 conditionals are LightBlue for better distinction.
 
 
+FORTH						*forth.vim* *ft-forth-syntax*
+
+Files matching "*.fs" could be F# or Forth.  If the automatic detection
+doesn't work for you, or you don't edit F# at all, use this in your
+startup vimrc: >
+   :let filetype_fs = "forth"
+
+
 FORTRAN					*fortran.vim* *ft-fortran-syntax*
 
 Default highlighting and dialect ~

runtime/filetype.vim

@@ -632,7 +632,10 @@ au BufNewFile,BufRead auto.master		setf conf
 au BufNewFile,BufRead *.mas,*.master		setf master
 
 " Forth
-au BufNewFile,BufRead *.fs,*.ft,*.fth		setf forth
+au BufNewFile,BufRead *.ft,*.fth		setf forth
+
+" F# or Forth
+au BufNewFile,BufRead *.fs			call dist#ft#FTfs()
 
 " Reva Forth
 au BufNewFile,BufRead *.frt			setf reva

runtime/scripts.vim

@@ -198,6 +198,10 @@ if s:line1 =~# "^#!"
   elseif s:name =~# 'fish\>'
     set ft=fish
 
+    " Gforth
+  elseif s:name =~# 'gforth\>'
+    set ft=forth
+
   endif
   unlet s:name