Fix rendering of Traditional Mongolian script

* lisp/international/characters.el: Set punctuation syntax for Po
characters from the Mongolian block
* lisp/international/fontset.el (setup-default-fontset): Add
fontset setting for Traditional Mongolic.
* lisp/language/misc-lang.el (composition-function-table): Add
rules for Traditional Mongolic.  (Bug#63028)

lisp/international/characters.el

@@ -695,6 +695,16 @@ with L, LRE, or LRO Unicode bidi character type.")
     (set-case-syntax c "_" tbl)
     (setq c (1+ c)))
 
+  ;; Traditional Mongolian
+  (setq c #x1800)
+  (while (<= c #x180A)
+    (set-case-syntax c "." tbl)
+    (setq c (1+ c)))
+  (setq c #x11660)
+  (while (<= c #x1166C)
+    (set-case-syntax c "." tbl)
+    (setq c (1+ c)))
+
   ;; Coptic
   ;; There's no Coptic category.  However, Coptic letters that are
   ;; part of the Greek block above get the Greek category, and those

lisp/international/fontset.el

@@ -648,6 +648,8 @@
 	     (nil . "MuleArabic-1")
 	     (nil . "MuleArabic-2")
 	     (nil . "ISO8859-6"))
+     (mongolian ,(font-spec :registry "iso10646-1"
+			    :otf '(mong nil (init medi fina))))
 
      (hebrew ,(font-spec :registry "iso10646-1" :script 'hebrew)
 	     (nil . "ISO8859-8"))

lisp/language/misc-lang.el

@@ -339,6 +339,20 @@ Coptic language using the Coptic script is supported in this
 language environment."))
  '("Misc"))
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Traditional Mongolian
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(set-char-table-range
+ composition-function-table
+ '(#x1820 . #x18AF)
+ (list (vector "[\u200C\u200D][\u1820-\u18AF][\u200C\u200D]?"
+               1 'font-shape-gstring)
+       (vector "[\u1820-\u18AF][\u200C\u200D]" 0 'font-shape-gstring)
+       (vector "[\u1820-\u18AF\u202F\u180B-\u180F\u1807]+"
+               0 'font-shape-gstring)))
+
+
 (provide 'misc-lang)
 
 ;;; misc-lang.el ends here