vim-patch:9.1.1140: filetype: m17ndb files are not detected (#32618)

Problem:  filetype: m17ndb files are not detected
Solution: detect m17ndb files as m17ndb filetype,
          include filetype, syntax and indent files for the
          new filetype (David Mandelberg).

References:

https://www.nongnu.org/m17n/manual-en/m17nDBFormat.html describes the
format. https://git.savannah.nongnu.org/cgit/m17n/m17n-db.git/tree/ has
examples of the files.

closes: vim/vim#16696

https://github.com/vim/vim/commit/ed7d8e55ac232758fc14fd132994b4a09b19350b

Also adjust the xkb parent pattern according to dev_vimpatch.txt.

Co-authored-by: David Mandelberg <david@mandelberg.org>

5 files changed, 92 insertions, 1 deletions

diff --git a/runtime/ftplugin/m17ndb.vim b/runtime/ftplugin/m17ndb.vim
new file mode 100644
index 0000000000..e4457cef9d
--- /dev/null
+++ b/runtime/ftplugin/m17ndb.vim
@@ -0,0 +1,17 @@
+" Vim filetype plugin
+" Language:	m17n database
+" Maintainer:	David Mandelberg <david@mandelberg.org>
+" Last Change:	2025 Feb 21
+
+if exists('b:did_ftplugin')
+  finish
+endif
+let b:did_ftplugin = 1
+
+setlocal comments=:;;;,:;;,:;
+setlocal commentstring=;\ %s
+setlocal iskeyword=!-~,@,^34,^(,^),^92
+setlocal lisp
+setlocal lispwords=
+
+let b:undo_ftplugin = "setlocal comments< commentstring< iskeyword< lisp< lispwords<"
diff --git a/runtime/indent/m17ndb.vim b/runtime/indent/m17ndb.vim
new file mode 100644
index 0000000000..d25aafe135
--- /dev/null
+++ b/runtime/indent/m17ndb.vim
@@ -0,0 +1,14 @@
+" Vim indent file
+" Language:	m17n database
+" Maintainer:	David Mandelberg <david@mandelberg.org>
+" Last Change:	2025 Feb 21
+
+if exists("b:did_indent")
+  finish
+endif
+let b:did_indent = 1
+
+setlocal autoindent
+setlocal nosmartindent
+
+let b:undo_indent = "setlocal autoindent< smartindent<"
diff --git a/runtime/lua/vim/filetype.lua b/runtime/lua/vim/filetype.lua
index 66ee45587a..c47ce5e761 100644
--- a/runtime/lua/vim/filetype.lua
+++ b/runtime/lua/vim/filetype.lua
@@ -2325,13 +2325,42 @@ local pattern = {
     ['^Neomuttrc'] = detect_neomuttrc,
     ['%.neomuttdebug'] = 'neomuttlog',
   },
-  ['/%.?xkb/'] = {
+  ['xkb/'] = {
     ['/%.?xkb/compat/'] = detect_xkb,
     ['/%.?xkb/geometry/'] = detect_xkb,
     ['/%.?xkb/keycodes/'] = detect_xkb,
     ['/%.?xkb/symbols/'] = detect_xkb,
     ['/%.?xkb/types/'] = detect_xkb,
   },
+  ['m17n'] = {
+    ['/m17n/.*%.ali$'] = 'm17ndb',
+    ['/m17n/.*%.cs$'] = 'm17ndb',
+    ['/m17n/.*%.dir$'] = 'm17ndb',
+    ['/m17n/.*%.flt$'] = 'm17ndb',
+    ['/m17n/.*%.fst$'] = 'm17ndb',
+    ['/m17n/.*%.lnm$'] = 'm17ndb',
+    ['/m17n/.*%.mic$'] = 'm17ndb',
+    ['/m17n/.*%.mim$'] = 'm17ndb',
+    ['/m17n/.*%.tbl$'] = 'm17ndb',
+    ['/%.m17n%.d/.*%.ali$'] = 'm17ndb',
+    ['/%.m17n%.d/.*%.cs$'] = 'm17ndb',
+    ['/%.m17n%.d/.*%.dir$'] = 'm17ndb',
+    ['/%.m17n%.d/.*%.flt$'] = 'm17ndb',
+    ['/%.m17n%.d/.*%.fst$'] = 'm17ndb',
+    ['/%.m17n%.d/.*%.lnm$'] = 'm17ndb',
+    ['/%.m17n%.d/.*%.mic$'] = 'm17ndb',
+    ['/%.m17n%.d/.*%.mim$'] = 'm17ndb',
+    ['/%.m17n%.d/.*%.tbl$'] = 'm17ndb',
+    ['/m17n%-db/.*%.ali$'] = 'm17ndb',
+    ['/m17n%-db/.*%.cs$'] = 'm17ndb',
+    ['/m17n%-db/.*%.dir$'] = 'm17ndb',
+    ['/m17n%-db/.*%.flt$'] = 'm17ndb',
+    ['/m17n%-db/.*%.fst$'] = 'm17ndb',
+    ['/m17n%-db/.*%.lnm$'] = 'm17ndb',
+    ['/m17n%-db/.*%.mic$'] = 'm17ndb',
+    ['/m17n%-db/.*%.mim$'] = 'm17ndb',
+    ['/m17n%-db/.*%.tbl$'] = 'm17ndb',
+  },
   ['^%.'] = {
     ['^%.cshrc'] = detect.csh,
     ['^%.login'] = detect.csh,
diff --git a/runtime/syntax/m17ndb.vim b/runtime/syntax/m17ndb.vim
new file mode 100644
index 0000000000..8d63e6f918
--- /dev/null
+++ b/runtime/syntax/m17ndb.vim
@@ -0,0 +1,28 @@
+" Vim syntax file
+" Language:	m17n database
+" Maintainer:	David Mandelberg <david@mandelberg.org>
+" Last Change:	2025 Feb 21
+"
+" https://www.nongnu.org/m17n/manual-en/m17nDBFormat.html describes the
+" syntax, but some of its regexes don't match the code. read_element() in
+" https://git.savannah.nongnu.org/cgit/m17n/m17n-lib.git/tree/src/plist.c
+" seems to be a better place to understand the syntax.
+
+if exists("b:current_syntax")
+ finish
+endif
+let b:current_syntax = "m17ndb"
+
+syn match m17ndbSymbol /\([^\x00- ()"\\]\|\\\_.\)\+/
+syn match m17ndbComment ";.*$" contains=@Spell
+syn match m17ndbInteger "-\?[0-9]\+"
+syn match m17ndbInteger "[0#]x[0-9A-Fa-f]\+"
+syn match m17ndbCharacter "?\(\_[^\\]\|\\\_.\)"
+syn region m17ndbText start=/\Z"/ skip=/\\\\\|\\"/ end=/"/
+syn region m17ndbPlist matchgroup=m17ndbParen start="(" end=")" fold contains=ALL
+
+hi def link m17ndbCharacter Character
+hi def link m17ndbComment Comment
+hi def link m17ndbInteger Number
+hi def link m17ndbParen Delimiter
+hi def link m17ndbText String
diff --git a/test/old/testdir/test_filetype.vim b/test/old/testdir/test_filetype.vim
index eb261077a3..37337d9b54 100644
--- a/test/old/testdir/test_filetype.vim
+++ b/test/old/testdir/test_filetype.vim
@@ -446,6 +446,9 @@ func s:GetFilenameChecks() abort
     \ 'luau': ['file.luau'],
     \ 'lynx': ['lynx.cfg'],
     \ 'lyrics': ['file.lrc'],
+    \ 'm17ndb': ['any/m17n/file.ali', 'any/m17n/file.cs', 'any/m17n/file.dir', 'any/m17n/file.flt', 'any/m17n/file.fst', 'any/m17n/file.lnm', 'any/m17n/file.mic', 'any/m17n/file.mim', 'any/m17n/file.tbl',
+    \            'any/.m17n.d/file.ali', 'any/.m17n.d/file.cs', 'any/.m17n.d/file.dir', 'any/.m17n.d/file.flt', 'any/.m17n.d/file.fst', 'any/.m17n.d/file.lnm', 'any/.m17n.d/file.mic', 'any/.m17n.d/file.mim', 'any/.m17n.d/file.tbl',
+    \            'any/m17n-db/file.ali', 'any/m17n-db/file.cs', 'any/m17n-db/file.dir', 'any/m17n-db/FLT/file.flt', 'any/m17n-db/file.fst', 'any/m17n-db/LANGDATA/file.lnm', 'any/m17n-db/file.mic', 'any/m17n-db/MIM/file.mim', 'any/m17n-db/file.tbl'],
     \ 'm3build': ['m3makefile', 'm3overrides'],
     \ 'm3quake': ['file.quake', 'cm3.cfg'],
     \ 'm4': ['file.at', '.m4_history'],