patch 8.2.4746: supercollider filetype not recognized

Problem:    Supercollider filetype not recognized.
Solution:   Match file extentions and check file contents to detect
            supercollider. (closes #10142)

runtime/autoload/dist/ft.vim

@@ -769,6 +769,28 @@ export def SQL()
   endif
 enddef
 
+# This function checks the first 25 lines of file extension "sc" to resolve
+# detection between scala and SuperCollider
+export def FTsc()
+  for lnum in range(1, min([line("$"), 25]))
+    if getline(lnum) =~# '[A-Za-z0-9]*\s:\s[A-Za-z0-9]\|var\s<\|classvar\s<\|\^this.*\||\w*|\|+\s\w*\s{\|\*ar\s'
+      setf supercollider
+      return
+    endif
+  endfor
+  setf scala
+enddef
+
+# This function checks the first line of file extension "scd" to resolve
+# detection between scdoc and SuperCollider
+export def FTscd()
+  if getline(1) =~# '\%^\S\+(\d[0-9A-Za-z]*)\%(\s\+\"[^"]*\"\%(\s\+\"[^"]*\"\)\=\)\=$'
+    setf scdoc
+  else
+    setf supercollider
+  endif
+enddef
+
 # If the file has an extension of 't' and is in a directory 't' or 'xt' then
 # it is almost certainly a Perl test file.
 # If the first line starts with '#' and contains 'perl' it's probably a Perl

runtime/filetype.vim

@@ -206,12 +206,12 @@ au BufNewFile,BufRead *.iba,*.ibi		setf ibasic
 au BufNewFile,BufRead *.fb			setf freebasic
 
 " Batch file for MSDOS. See dist#ft#FTsys for *.sys
-au BufNewFile,BufRead *.bat 			setf dosbatch
+au BufNewFile,BufRead *.bat			setf dosbatch
 " *.cmd is close to a Batch file, but on OS/2 Rexx files also use *.cmd.
 au BufNewFile,BufRead *.cmd
 	\ if getline(1) =~ '^/\*' | setf rexx | else | setf dosbatch | endif
 " ABB RAPID or Batch file for MSDOS.
-au BufNewFile,BufRead *.sys\c 			call dist#ft#FTsys()
+au BufNewFile,BufRead *.sys\c			call dist#ft#FTsys()
 
 " Batch file for 4DOS
 au BufNewFile,BufRead *.btm			call dist#ft#FTbtm()
@@ -1144,7 +1144,7 @@ au BufNewFile,BufRead *.mms			call dist#ft#FTmms()
 au BufNewFile,BufRead *.mmp			setf mmp
 
 " ABB Rapid, Modula-2, Modsim III or LambdaProlog
-au BufNewFile,BufRead *.mod\c 			call dist#ft#FTmod()
+au BufNewFile,BufRead *.mod\c			call dist#ft#FTmod()
 
 " Modula-2  (.md removed in favor of Markdown, see dist#ft#FTmod for *.MOD)
 au BufNewFile,BufRead *.m2,*.DEF,*.mi		setf modula2
@@ -1634,16 +1634,22 @@ au BufNewFile,BufRead *.sass			setf sass
 au BufNewFile,BufRead *.sa			setf sather
 
 " Scala
-au BufNewFile,BufRead *.scala,*.sc		setf scala
+au BufNewFile,BufRead *.scala			setf scala
 
 " SBT - Scala Build Tool
 au BufNewFile,BufRead *.sbt			setf sbt
 
+" SuperCollider
+au BufNewFile,BufRead *.sc			call dist#ft#FTsc()
+
+au BufNewFile,BufRead *.quark			setf supercollider
+
+" scdoc
+au BufNewFile,BufRead *.scd			call dist#ft#FTscd()
+
 " Scilab
 au BufNewFile,BufRead *.sci,*.sce		setf scilab
 
-" scdoc
-au BufNewFile,BufRead *.scd			setf scdoc
 
 " SCSS
 au BufNewFile,BufRead *.scss			setf scss