patch 9.1.1764: filetype: CODEOWNERS file not recognized

Problem:  filetype: CODEOWNERS file not recognized
Solution: Detect CODEOWNERS file as codeowners filetype, include a
          syntax and filetype plugin (Jon Parise).

CODEOWNERS files define code ownership rules for GitHub-hosted (and
other) repositories. The syntax is similar to 'gitignore' files but
differs in enough ways to warrant its own filetype.

References:
- https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-code-owners

closes: #18299

Signed-off-by: Jon Parise <jon@indelible.org>
Signed-off-by: Christian Brabandt <cb@256bit.org>

.github/MAINTAINERS

@@ -136,6 +136,7 @@ runtime/ftplugin/chatito.vim				@ObserverOfTime
 runtime/ftplugin/chicken.vim				@evhan
 runtime/ftplugin/clojure.vim				@axvr
 runtime/ftplugin/cmakecache.vim				@ribru17
+runtime/ftplugin/codeowners.vim				@jparise
 runtime/ftplugin/cook.vim				@ribru17
 runtime/ftplugin/cs.vim					@nickspoons
 runtime/ftplugin/csh.vim				@dkearns
@@ -456,6 +457,7 @@ runtime/syntax/chatito.vim				@ObserverOfTime
 runtime/syntax/chicken.vim				@evhan
 runtime/syntax/chuck.vim				@andreacfromtheapp
 runtime/syntax/clojure.vim				@axvr
+runtime/syntax/codeowners.vim				@jparise
 runtime/syntax/cs.vim					@nickspoons
 runtime/syntax/csv.vim					@habamax
 runtime/syntax/cucumber.vim				@tpope
@@ -686,3 +688,5 @@ src/po/sr.po						@eevan78
 src/po/tr.po						@bitigchi
 src/po/uk.po						@sakhnik
 src/xxd/						@jnweiger
+
+# vim:ft=codeowners

runtime/filetype.vim

@@ -398,6 +398,9 @@ au BufNewFile,BufRead *.ck			setf chuck
 " Comshare Dimension Definition Language
 au BufNewFile,BufRead *.cdl			setf cdl
 
+" Codeowners
+au BufNewFile,BufRead CODEOWNERS		setf codeowners
+
 " Conary Recipe
 au BufNewFile,BufRead *.recipe			setf conaryrecipe
 

runtime/ftplugin/codeowners.vim

@@ -0,0 +1,14 @@
+" Vim filetype plugin
+" Language:	codeowners
+" Maintainer:	Jon Parise <jon@indelible.org>
+" Last Change:	2025 Sep 14
+"
+if exists('b:did_ftplugin')
+  finish
+endif
+let b:did_ftplugin = 1
+
+setl comments=:# commentstring=#\ %s
+setl formatoptions-=t formatoptions+=croql
+
+let b:undo_ftplugin = 'setl com< cms< fo<'

runtime/syntax/codeowners.vim

@@ -0,0 +1,23 @@
+" Vim syntax file
+" Language:	codeowners
+" Maintainer:	Jon Parise <jon@indelible.org>
+" Last Change:	2025 Sep 14
+
+if exists('b:current_syntax')
+  finish
+endif
+
+" Comments
+syn match codeownersComment /#.*$/ contains=codeownersTodo,@Spell
+syn keyword codeownersTodo TODO FIXME XXX contained
+
+" Patterns
+syn match codeownersPattern /^#\@![^#]*/ contains=codeownersGlob
+syn match codeownersGlob /^\S\+/ contained nextgroup=codeownersOwner skipwhite
+syn match codeownersOwner /\S\+/ contained nextgroup=codeownersOwner skipwhite
+
+hi def link codeownersComment Comment
+hi def link codeownersOwner Identifier
+hi def link codeownersTodo Todo
+
+let b:current_syntax = 'codeowners'

runtime/syntax/testdir/dumps/codeowners_00.dump

@@ -0,0 +1,20 @@
+>#+0#0000e05#ffffff0| |T|h|i|s| |i|s| |a| |c|o|m@1|e|n|t|.| +0#0000000&@54
+|#+0#0000e05&| |E|a|c|h| |l|i|n|e| |i|s| |a| |f|i|l|e| |p|a|t@1|e|r|n| |f|o|l@1|o|w|e|d| |b|y| |o|n|e| |o|r| |m|o|r|e| |o|w|n|e|r|s|.| +0#0000000&@13
+@75
+|*| @6|@+0#00e0e07&|g|l|o|b|a|l|-|o|w|n|e|r|1| +0#0000000&|@+0#00e0e07&|g|l|o|b|a|l|-|o|w|n|e|r|2| +0#0000000&@37
+|*|.|j|s| @3|@+0#00e0e07&|j|s|-|o|w|n|e|r| +0#0000000&|#+0#0000e05&|T|h|i|s| |i|s| |a|n| |i|n|l|i|n|e| |c|o|m@1|e|n|t|.| +0#0000000&@29
+|*|.|g|o| @3|d+0#00e0e07&|o|c|s|@|e|x|a|m|p|l|e|.|c|o|m| +0#0000000&@50
+|*|.|t|x|t| @2|@+0#00e0e07&|o|c|t|o|-|o|r|g|/|o|c|t|o|c|a|t|s| +0#0000000&@48
+|/|a|/|b|/| @2|@+0#00e0e07&|d|o|c|t|o|c|a|t| +0#0000000&@57
+|d|o|c|s|/|*| @1|d+0#00e0e07&|o|c|s|@|e|x|a|m|p|l|e|.|c|o|m| +0#0000000&|@+0#00e0e07&|o|t|h|e|r| +0#0000000&@43
+|*@1|/|l|o|g|s| |@+0#00e0e07&|o|c|t|o|c|a|t| +0#0000000&@58
+@75
+|#+0#0000e05&| |v|i|m|:| |s|e|t| |f|t|=|c|o|d|e|o|w|n|e|r|s|:| +0#0000000&@49
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|1|,|1| @10|A|l@1| 

runtime/syntax/testdir/input/codeowners.txt

@@ -0,0 +1,12 @@
+# This is a comment.
+# Each line is a file pattern followed by one or more owners.
+
+*       @global-owner1 @global-owner2
+*.js    @js-owner #This is an inline comment.
+*.go	docs@example.com
+*.txt	@octo-org/octocats
+/a/b/	@doctocat
+docs/*	docs@example.com @other
+**/logs @octocat
+
+# vim: set ft=codeowners:

src/testdir/test_filetype.vim

@@ -189,6 +189,7 @@ def s:GetFilenameChecks(): dict<list<string>>
     cmusrc: ['any/.cmus/autosave', 'any/.cmus/rc', 'any/.cmus/command-history', 'any/.cmus/file.theme', 'any/cmus/rc', 'any/cmus/file.theme', '/.cmus/autosave', '/.cmus/command-history', '/.cmus/file.theme', '/.cmus/rc', '/cmus/file.theme', '/cmus/rc'],
     cobol: ['file.cbl', 'file.cob'],
     coco: ['file.atg'],
+    codeowners: ['CODEOWNERS'],
     conaryrecipe: ['file.recipe'],
     conf: ['auto.master', 'file.conf', 'texdoc.cnf', '.x11vncrc', '.chktexrc', '.ripgreprc', 'ripgreprc', 'file.ctags'],
     config: ['/etc/hostname.file', 'any/etc/hostname.file', 'configure.in', 'configure.ac', 'file.at', 'aclocal.m4'],

src/version.c

@@ -724,6 +724,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1764,
 /**/
     1763,
 /**/