vim-patch:8.2.4793: recognizing Maxima filetype even though it might be another

Problem:    Recognizing Maxima filetype even though it might be another.
Solution:   Remove *.mc and *.dem patterns from Maxima files
928a131356

runtime/filetype.vim

@@ -151,18 +151,21 @@ au BufNewFile,BufRead *.asp
 	\   setf aspvbs |
 	\ endif
 
-" Grub (must be before catch *.lst)
+" Grub (must be before pattern *.lst)
 au BufNewFile,BufRead */boot/grub/menu.lst,*/boot/grub/grub.conf,*/etc/grub.conf setf grub
 
 " Maxima, see:
 " https://maxima.sourceforge.io/docs/manual/maxima_71.html#file_005ftype_005fmaxima
-au BufNewFile,BufRead *.mc,*.demo,*.dem,*.dm{1,2,3,t},*.wxm,maxima-init.mac setf maxima
+" Must be before the pattern *.mac.
+" *.dem omitted - also used by gnuplot demos
+" *.mc omitted - used by dist#ft#McSetf()
+au BufNewFile,BufRead *.demo,*.dm{1,2,3,t},*.wxm,maxima-init.mac setf maxima
 
 " Assembly (all kinds)
 " *.lst is not pure assembly, it has two extra columns (address, byte codes)
 au BufNewFile,BufRead *.asm,*.[sS],*.[aA],*.mac,*.lst	call dist#ft#FTasm()
 
-" Macro (VAX)
+" Assembly - Macro (VAX)
 au BufNewFile,BufRead *.mar			setf vmasm
 
 " Atlas
@@ -1678,7 +1681,8 @@ au BufNewFile,BufRead *.siv,*.sieve		setf sieve
 " Sendmail
 au BufNewFile,BufRead sendmail.cf		setf sm
 
-" Sendmail .mc files are actually m4.  Could also be MS Message text file.
+" Sendmail .mc files are actually m4.  Could also be MS Message text file or
+" Maxima.
 au BufNewFile,BufRead *.mc			call dist#ft#McSetf()
 
 " Services

runtime/lua/vim/filetype.lua

@@ -389,6 +389,12 @@ local extension = {
   mason = "mason",
   master = "master",
   mas = "master",
+  demo = "maxima",
+  dm1 = "maxima",
+  dm2 = "maxima",
+  dm3 = "maxima",
+  dmt = "maxima",
+  wxm = "maxima",
   mel = "mel",
   mf = "mf",
   mgl = "mgl",
@@ -1013,6 +1019,7 @@ local filename = {
   [".mailcap"] = "mailcap",
   ["/etc/man.conf"] = "manconf",
   ["man.config"] = "manconf",
+  ["maxima-init.mac"] = "maxima",
   ["meson.build"] = "meson",
   ["meson_options.txt"] = "meson",
   ["/etc/conf.modules"] = "modconf",

src/nvim/testdir/test_filetype.vim

@@ -337,7 +337,7 @@ let s:filename_checks = {
     \ 'markdown': ['file.markdown', 'file.mdown', 'file.mkd', 'file.mkdn', 'file.mdwn', 'file.md'],
     \ 'mason': ['file.mason', 'file.mhtml', 'file.comp'],
     \ 'master': ['file.mas', 'file.master'],
-    \ 'maxima': ['file.mc', 'file.demo', 'file.dem', 'file.dmt', 'file.dm1', 'file.dm2', 'file.dm3',
+    \ 'maxima': ['file.demo', 'file.dmt', 'file.dm1', 'file.dm2', 'file.dm3',
     \            'file.wxm', 'maxima-init.mac'],
     \ 'mel': ['file.mel'],
     \ 'meson': ['meson.build', 'meson_options.txt'],